As filed with the Securities and Exchange Commission on October 4, 2019July 2, 2021

Registration No. 333-          

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORMS-4

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

GLACIER BANCORP, INC.

(Exact name of registrant as specified in its charter)

49 Commons Loop, Kalispell, Montana 59901 (406)756-4200

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

RANDALL M. CHESLER

President and Chief Executive Officer

49 Commons Loop

Kalispell, Montana 59901

(406)756-4200

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies of communications to:

Approximate date of commencement of proposed sale of securities to the public:

As soon as practicable after this Registration Statement becomes effective and upon completion of the merger described in the enclosed document.

If the securities being registered on this Form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box.  ☐

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, anon-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided purchase to Section 7(a)(2)(B) of the Securities Act.  ☐

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

Information contained herein is subject to completion or amendment. A registration statement relating to these securities has been filed with the Securities and Exchange Commission. These securities may not be sold prior to the time the registration statement becomes effective. This document shall not constitute an offer to sell nor shall there be any sale of these securities in any jurisdiction in which such offer or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction.

PRELIMINARY—SUBJECT TO COMPLETION—DATED OCTOBER 4, 2019JULY 2, 2021

MERGER PROPOSED – YOUR VOTE IS VERY IMPORTANT

Dear State Bank Corp.Altabancorp Shareholders:

As you may know, the boards of directors of State Bank Corp.Altabancorp (“SBC”AB”) and Glacier Bancorp, Inc., Kalispell, Montana (“Glacier”) have each unanimously approved a merger of SBCAB with and into Glacier, subject to approval by SBCAB shareholders and appropriate bank regulators. Immediately following the merger, SBC’sAB’s subsidiary State Bank of ArizonaAltabank (the “Bank”) will be merged into Glacier’s subsidiary Glacier Bank (“Glacier Bank”), subject to approval of the appropriate bank regulators.

Under the terms of the Plan and Agreement of Merger, dated September 30, 2019May 18, 2021 (the “merger agreement”), each outstanding AB common share as of SBC common stockthe effective time (including each share issued upon settlement of each unvested restricted stock)stock unit) will be exchanged for a “unit” comprised of $1.69 and 0.37060.7971 shares of Glacier common stock (the “per share stock consideration”), subject to certain adjustments.adjustments, with cash paid in lieu of fractional shares. The common stock of Glacier trades on The NASDAQNasdaq Global Select Market under the symbol “GBCI.” SBC’sThe common stock is currently quotedof AB trades on the OTC PinkThe Nasdaq Capital Market under the symbol “SBAZ.“ALTA.”

The per share stock portion of each unitconsideration is subject to adjustment in the event that the average closing price for Glacier common stock over a20-day period prior to closing is more than $47.31,$74.15 or less than $34.97, if such stock price has underperformed the KBW Regional Bank Index by more than fifteen percentage points, or less than $32.91.$49.43. In such event either Glacier or SBC,AB, respectively, may provide notice to terminate the merger agreement, but the merger agreement will not be terminated if either SBCAB or Glacier, as the case may be, elects to adjust the consideration to be issued in the merger, as described in this proxy statement/prospectus. Glacier may also elect to pay additional cash consideration in lieu of increasing the number of shares to be issued in the merger.

The cash portion of each unitper share stock consideration is subject to further adjustment depending on SBC’sif AB’s closing capital, prior to the closing of the merger, calculatedafter being adjusted in accordance with the terms of the merger agreement. If SBC’s capitalagreement, is less than the minimum required, which is $63,611,000$342,937,000 (subject to specified adjustments),. In any such event, the cash portion of each unitper share stock consideration will be reduced on a pro rataper share basis byin accordance with the amount of such deficiency. formula set forth in the merger agreement.

If SBC’sAB’s closing capital, after being adjusted in accordance with the terms of the merger agreement, is in excess of the minimum required, SBCAB may pay a special dividend to its shareholders in the amount of such excess.

Assuming for purposes of illustration only that (i)there is no increase or reduction of the cash portion of each unit, and(ii) the average closing price for Glacier common stock is $[]___], which was the closing price of Glacier common stock on [][___], 2019,2021, as quoted on The NASDAQNasdaq Global Select Market, for each of your shares of SBCAB common stock,shares, you will receive consideration with an estimated current value of $[]___], consisting of a combination of $1.69 in cash and 0.37060.7971 shares of Glacier common stock (valued at $[]).stock.

Assuming the exchange of all outstanding SBCAB common stockshares for stock and cash in accordance with the merger agreement and the per share stock portion of each unitconsideration is not adjusted as described above, SBCAB shareholders will, in the aggregate, receive approximately 3,007,353[___] shares of Glacier common stock in the merger, representing approximately 3.4%[___]% of Glacier’s outstanding common stock after taking into account Glacier shares to be issued in the merger.

SBCAB will hold a special shareholders’ meeting to vote on the merger agreement on [][___], 2019,2021, at [] []. m.[___] Mountain Standard Time, at [], Lake Havasu City, Arizona.Time. This special meeting will be held in virtual format only. Detailed instructions for participation can be found in the notice of special shareholder meeting that accompanies this proxy statement/prospectus. Whether or not you plan to attendparticipate in the special meeting virtually, please take the time to vote by voting over the Internet, by telephone or completing and mailing the enclosed form of proxy.Please give particular attention to the discussion under the heading “Risk Factors” beginning on page 1314 for risk factors relating to the merger which you should consider.

The board of directors of SBCAB has unanimously recommended that you vote FOR approval of the merger agreement and the other proposals described in this proxy statement/prospectus.

/s/ Len E. Williams

Neither the Federal Deposit Insurance Corporation, Securities and Exchange Commission, nor any state securities commission has approved the securities to be issued by Glacier or determined if this proxy statement/prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The shares of Glacier common stock to be issued in the merger are not savings or deposit accounts or other obligations of a bank and are not insured by the Federal Deposit Insurance Corporation, the Federal Deposit Insurance Fund or any other governmental agency. Such shares are not guaranteed by Glacier or SBCAB and are subject to investment risk, including the possible loss of principal.

This proxy statement/prospectus is dated [][___], 20192021, and is first being mailed to

SBCAB shareholders on or about [][___], 2019.2021.

STATE BANK CORP.

Lake Havasu City, Arizona 864031 East Main Street, American Fork, Utah 84003

NOTICE OF SPECIAL MEETING OF SHAREHOLDERS OF

TO BE HELD ON [], 2019ALTABANCORP^TM

TO THE SHAREHOLDERS OF STATE BANK CORP.:[    ], 2021

To the Shareholders of Altabancorp:

A special meeting of the shareholders of State Bank Corp.Altabancorp (“SBC”AB”) will be held on [][___], 2019, at [] [].m. Mountain Standard Time, at [], Lake Havasu City, Arizona.2021. The special meeting will be held in a virtual meeting format only. Please visit the website www.proxydocs.com/ALTAand enter your control number to register to attend the meeting. The deadline to register to attend the virtual special meeting is [__], 2021, at 5:00 p.m. Mountain Time. You are encouraged to vote your shares by telephone, by completing and mailing the enclosed form of proxy, or online in advance of the special meeting but may also vote during the meeting by following the instructions available on the meeting website. The special meeting will convene at [___] Mountain Time for the following purposes:

Holders of record of SBCAB common stockshares at the close of business on [][___], 2019,2021, the record date for the special meeting, are entitled to notice of and to vote at the special meeting or any adjournments or postponements of it. The affirmative vote of the holders of at least a majority of the outstanding shares of SBC’sAB’s common stock entitled to vote is required for approval of the merger agreement. To that end, SBC’sAB’s directors and executive officers and certain significant shareholders have signed agreements to vote their shares in favor of the merger agreement. As of the record date, such persons were entitled to vote [][_________] shares representing approximately [][____]% of all outstanding shares of SBCAB common stock, excluding shares of unvested restricted stock.shares. As of the record date, there were [][__________] AB common shares of SBC common stock outstanding, excluding [                    ] shares of unvested restricted stock, which do not have voting rights.outstanding.

Your vote is important. Whether or not you plan to attendparticipate in the special meeting virtually, we encourage you to submit a proxy to vote your shares as promptly as possible in order to make certain that you are represented at the meeting. You may submit a proxy over the Internet, as well as by telephone or by completing, signing, dating and promptly returning the accompanying proxy using the enclosed envelope. If for any reason you should desire to revoke your proxy, you may do so at any time before it is voted at the meeting.If you do not vote your shares, it will have the same effect as voting against the merger.

The board of directors of SBCAB has determined that the merger agreement is fair to, advisable, and in the best interests of SBCAB and its shareholders and unanimously recommends that you vote FOR approval of the merger agreement.agreement, FOR approval of the merger-related named executive officer compensation proposal, and FOR approval of the adjournment proposal. With regard to its recommendation that shareholders vote FOR approval of the merger agreement, the board of directors of SBCAB considered a number of factors, as discussed in “Background of and Reasons for the Merger” beginning on page 23.26. Such factors also constituted the reasons that the board of directors determined to approve the merger agreement and to recommend that SBCAB shareholders vote in favor of the merger agreement.

You will receive instructions on howImportant Notice Regarding the Availability of Proxy Materials for the

Special Shareholders Meeting to exchange your sharesbe held [____] 2021:

The proxy statement and notice of SBC common stock for the merger consideration promptly after the closing of the merger.special meeting are available at www.proxydocs.com/ALTA or from our Investor Relations website at www.altabancorp.com.

Lake Havasu City, Arizona

[], 2019

provided on the Glacier and AB websites is not part of this proxy statement/prospectus and is not incorporated herein by reference. Copies of the documents that Glacier or AB, respectively, files with the SEC can also be obtained, free of charge, by directing a written request to Glacier Bancorp, Inc., 49 Commons Loop, Kalispell, Montana 59901, ATTN: Corporate Secretary or to Altabancorp, 1 East Main Street, American Fork, Utah 84003, ATTN: Corporate Secretary.

Glacier has filed a registration statement on Form S-4 to register with the SEC Glacier common shares as specified therein. This proxy statement/prospectus is a part of that registration statement. As permitted by SEC rules, this document does not contain all of the information included in the registration statement or in the exhibits or schedules to the registration statement. You may read and copy the registration statement, including any amendments, schedules and exhibits, at the addresses set forth below. Statements contained in this document as to the contents of any contract or other documents referred to in this document are not necessarily complete. In each case, you should refer to the copy of the applicable contract or other document filed as an exhibit to the registration statement. This document incorporates important business and financial information about Glacier fromand AB that is not included in or delivered with this document, including incorporating by reference documents that Glacier hasand AB have previously filed with the SecuritiesSEC. These documents contain important information about the companies and Exchange Commission (“SEC”) and that are contained in or incorporated by reference into this proxy statement/prospectus. For a listing of Glacier documents incorporated by reference into this proxy statement/prospectus, please see the section entitledtheir financial condition. See “Where You Can Find More Information.” This information isThese documents are available for you to review at the SEC’s website athttp://www.sec.gov.

You may request copies of this proxy statement/prospectus and any of the documents incorporated by reference into this proxy statement/prospectus or other information concerning Glacier, without charge byto you upon written or oral request to the applicable company’s principal executive offices. The respective addresses and telephone or writtennumbers of such principal executive offices are listed below:

To obtain timely delivery of these documents, you must request directed to:

Glacier Bancorp, Inc.

49 Commons Loop

Kalispell, Montana 59901

ATTN: Ron Copher, Corporate Secretary

Telephone: (406)751-7706

Certain reports can also be found on Glacier’s website atwww.glacierbancorp.com.

Glacier’s common stock is traded on The NASDAQ Global Select Market under the symbol “GBCI.”

You will not be charged for the documents that you request.If you would like to request documents, please do so byinformation no later than [], 2019    ], 2021, in order to receive them before the SBC special shareholders’ meeting.meeting of AB shareholders (the “AB special meeting”).

State Bank Corp.

SBC does not have a class of securities registeredGlacier common shares, par value $0.01 per share, are traded on the Nasdaq Global Select Market, under Section 12 of the Securities Exchange Act of 1934 (the “Exchange Act”), is not subject tosymbol “GBCI,” and AB common shares, par value $0.01 per share, are traded on The Nasdaq Capital Market under the reporting requirements of Section 13(a) or 15(d) of the Exchange Act, and accordingly does not file documents or reports with the SEC.

If you have questions concerning the merger or this proxy statement/prospectus, would like additional copies of this proxy statement/prospectus, would like copies of SBC’s articles of incorporation or bylaws, or would like copies of SBC’s historical consolidated financial statements or need help voting your shares, please contact:

State Bank Corp.

1771 McCulloch Boulevard

Lake Havasu City, Arizona 86403

ATTN: Karen Gibbs, Corporate Secretary

(928)302-5165symbol “ALTA.”

TABLE OF CONTENTS

Appendix A – Plan and Agreement of Merger, dated as of May 18, 2021

Appendix B – Opinion of Keefe, Bruyette & Woods, Inc., Financial Advisor to Altabancorp

i

QUESTIONS AND ANSWERS

Why am I receiving these materials?

We are sending you these materials to solicit your proxy to vote in favor of the merger and to help you decide how to vote your shares of State Bank Corp.Altabancorp (“SBC”AB”) common stock with respect to its proposed merger with Glacier Bancorp, Inc. (“Glacier”). The merger cannot be completed unless SBCAB receives the affirmative vote of the holders of at least a majority of the outstanding shares of SBC’sAB’s common stock entitled to vote on the matter. SBCAB is holding a special meeting of shareholders to vote on proposals relating to the merger. Information about the special meeting is contained in this document. See “SBC“AB Special Shareholders Meeting.”

This document is both a proxy statement of SBCAB and a prospectus of Glacier. It is a proxy statement because the officers and board of directors of SBCAB (the “SBC“AB Board”) are soliciting proxies from SBC’sAB’s shareholders in connection with voting on the merger. It is a prospectus because Glacier will issue shares of its common stock in exchange for AB common shares of SBC common stock as a portion of the consideration to be paid in the merger.

What will happen in the merger?

In the proposed merger, SBCAB will merge with and into Glacier, with Glacier surviving the merger. Immediately following the merger, State Bank of ArizonaAltabank (the “Bank”) will be merged into Glacier’s subsidiary Glacier Bank. Shares of Glacier will continue to trade on The NASDAQNasdaq Global Select Market, with the trading symbol “GBCI.”

What will SBCAB shareholders receive in the merger?

Under the terms of the merger agreement, each share of SBCAB common stockshare (including each share to be issued upon settlement of each unvested restricted stock)stock unit (“RSU”)) will be exchanged for a “unit” comprised of 0.37060.7971 shares of Glacier common stock and $1.69 in cash,(the “per share stock consideration”), subject to adjustment as described below.certain adjustments, with cash paid in lieu of fractional shares.

Assuming for purposes of illustration only that the average closing price for Glacier common stock is $[]___] (which was the closing price forof Glacier common stock on [][___], 2019)2021), each share of SBCAB common stockshare would be exchanged for 0.37060.7971 shares of Glacier common stock with a total value equal to $[], in addition to the cash consideration of $1.69 per share.___].

The per share stock portion of each unitconsideration may be adjusted in certain circumstances based on whether Glacier common stock is trading either higher or lower than prices specified in the merger agreement immediately prior to the closing of the merger, in order to avoid termination of the merger agreement.

The cash portion of each unitIn addition, the per share stock consideration will be subject to reduction if the “SBC“AB Closing Capital,” as defined in the merger agreement, is less than the target of $63,611,000,$342,937,000, subject to certain adjustments. In such event, the cash portionnumber of each unitshares of Glacier common stock to be issued will be reduced on a pro rataper-share basis byin accordance with the amount of such deficiency.formula set forth in the merger agreement.

If the SBCAB Closing Capital exceeds $63,611,000,$342,937,000, subject to certain adjustments, SBCAB may, upon written notice to Glacier and effective immediately prior to the closing of the merger, declare and pay a special dividend to its shareholders in the amount of such excess.

By voting to approve the merger agreement, SBCAB shareholders will give the SBCAB Board the authority to elect to cause SBCAB to accept a reduction on aper-share basis of the number of shares of Glacier common stock to be issued in the merger if the Glacier average closing price exceeds $47.31,$74.15, as described below. See “The Merger – Termination of the Merger Agreement.”

described above, SBCAB shareholders will receive in the aggregate, approximately 3,007,353an estimated 15,129,749 shares of Glacier common stock in the merger, representing approximately 3.4%13.7% of Glacier’s outstanding common stock after taking into account Glacier shares to be issued in the merger.

How are outstanding AB stock options and RSUs addressed in the merger agreement?

Under the terms of the merger agreement, when the merger agreement becomes effective (the “effective time”), each outstanding RSU under the People’s Utah Bancorp 2014 Incentive Plan, the Altabancorp 2020 Equity Incentive Plan and the People’s Utah Bancorp Amended and Restated 2008 Stock Incentive Plan (the “AB Stock Plans”) will automatically vest and be settled, and each AB common share issued as a result will have the right to receive the per share stock consideration and cash in lieu of fractional AB common shares. Outstanding options to purchase AB common shares under the AB Stock Plans (the “AB Options”), whether vested or unvested, will be automatically canceled at the effective time, and the holders of AB Options will be paid in cash an amount per share equal to the spread, if any, between (a) the product of the Glacier average closing price (as defined in the merger agreement) multiplied by the per share stock consideration and (b) the exercise price per share of such AB Option, net of any cash which must be withheld under applicable tax laws. Any AB Option that has an exercise price per share that is greater than the total consideration value per share will be cancelled without any payment.

Will I receive any fractional shares of Glacier common stock as part of the merger consideration?

No. Glacier will not issue any fractional shares of Glacier common stock in the merger. Instead, Glacier will pay you the cash value of a fractional share (without interest) in an amount determined by multiplying the fractional share interest to which you would otherwise be entitled by the average of the closing sales prices of one share of Glacier common stock on The NASDAQNasdaq Global Select Market for the 20 trading days ending on the tenth business day immediately preceding the effective date of the merger.

How soon after the merger is completed can I expect to receive my merger consideration?

Glacier will work with its exchange agent, American Stock Transfer & Trust Company, LLC, to complete the exchange of your SBCAB stock certificates for consideration payable in the merger as promptly as practicable following the completion of the merger.

Will I be able to trade the shares of Glacier common stock that I receive in the merger?

You may freely trade the shares of Glacier common stock issued in the merger, unless you are an “affiliate” of Glacier as defined by Rule 144 under the Securities Act of 1933, as amended. Affiliates consist of individuals or entities that control, are controlled by or are under the common control with Glacier, and include the executive officers and directors of Glacier after the merger and may include significant shareholders of Glacier.

When will the merger occur?

We presently expect to complete the merger as early asduring the fourth quarter of 2019.2021. The actual timing of the transaction is subject to a number of factors (primarily regulatory approvals), many of which are beyond the control of Glacier and SBC.AB. The merger is conditioned upon and will occur after the approval of the merger agreement by the affirmative vote of holders of at least a majority of the outstanding shares of SBCAB common stockshares entitled to vote on the matter at the SBCAB special meeting, after the merger has received regulatory approvals, and following the satisfaction or waiver of the other conditions to the merger described in the merger agreement and summarized under “The Merger” below.

The merger agreement provides that in the event the closing has not occurred by November 30, 2019,2021, the first date on which the closing may occur is February 29, 2020.January 31, 2022.

If the merger does not occur by April 30, 2020,February 28, 2022, either Glacier or SBCAB may unilaterally terminate the merger agreement, subjectagreement. However, if as of February 28, 2022, all required regulatory approvals have not been obtained, then the deadline for consummation of the merger will be extended to an extensionon or before April 30, 2022, if either Glacier or AB notifies the other party in writing on or prior to February 28, 2022, of its election to extend such date under certain circumstances.date.

When and where will the special meeting take place?

SBCAB will hold a special meeting of its shareholders on [][___], 2019,2021, at [] [].m.[___] Mountain StandardTime. The special meeting will be held in virtual meeting format only. In order to attend the special meeting, AB shareholders must register at www.proxydocs.com/ALTA by 5:00 p.m. Mountain Time at []on [__], Lake Havasu City, Arizona.2021.

You may cast your vote by submitting a proxy through the Internet or by telephone by following the instructions included on the enclosed proxy card or by mail by completing, signing and dating the enclosed proxy card and returning it to us promptly in the enclosed envelope. Submitting a proxy through the Internet or by telephone or returning the proxy card will not affect your right to attend the special meeting by virtual means and vote.

If you choose to vote your shares in person at the virtual special meeting, please bringyou should follow the enclosed proxy card and proof of identification.instructions available on the shareholder meeting website.

If your shares are registered in “street name” in the name of a broker or other nominee and you wish to vote at the special meeting, you will need to obtain a legal proxy from your bank or brokerage firm. Please consult the voting form sent to you by your bank or broker to determine how to obtain a legal proxy in order to vote in person at the meeting.

If my shares are held in “street name” by my broker, bank or other nominee, will my broker, bank or other nominee automatically vote my shares for me?

No. Your broker, bank or other nominee will not vote your shares unless you provide instructions to your broker, bank or other nominee on how to vote. You should instruct your broker, bank or other nominee to vote your shares by following the instructions provided by the broker, bank or nominee with this proxy statement/prospectus.

How does the SBCAB Board recommend that I vote?

The SBCAB Board unanimously recommends that SBCAB shareholders vote “FOR” the proposals described in this proxy statement/prospectus, including in favor of approval of the merger agreement.agreement and the merger-related named executive compensation proposal.

What do I need to do now?

We encourage you to read this proxy statement/prospectus and related information in its entirety. Important information is presented in greater detail elsewhere in this document, and documents governing the merger are attached as appendices to this proxy statement/prospectus. In addition, much of the business and financial information about Glacier that may be important to you is incorporated by reference into this document from documents separately filed by Glacier with the Securities and Exchange Commission (“SEC”). This means that important disclosure obligations to you are satisfied by referring you to one or more documents separately filed with the SEC.

Following review of this proxy statement/prospectus,please submit a proxy through the Internet, by telephone or by completing, signing, and dating the enclosed proxy card and return it in the enclosed envelopeas soon as possible so that your shares of SBCAB common stockshares can be voted at SBC’sAB’s special meeting of shareholders.

What happens if I sell my shares after the record date but before the special meeting?

The record date of the special meeting is earlier than the date of the special meeting and the date that the merger is expected to be completed. If you sell or otherwise transfer your shares after the record date, but before the date of the special meeting, you will retain your right to vote at the special meeting, but you will not have the right to receive the merger consideration to be received by shareholders in the merger. In order to receive the merger consideration, a shareholder must hold his or her shares through completion of the merger.

What do I do if I receive more than one proxy statement/prospectus or set of voting instructions?

If you hold shares directly as a record holder and also in “street name” or otherwise through a nominee, you may receive more than one proxy statement/prospectus and/or set of voting instructions relating to the special meeting. These should each be voted and/or returned separately in order to ensure that all of your shares are voted.

Should I send in my common stock certificates now?

No.Please do not send your SBCAB common stockshare certificates with your proxy card. You will receive written instructions from Glacier’s exchange agent promptly following the closing of the merger on how to exchange your SBCAB common stockshare certificates for the merger consideration.

What risks should I consider in deciding whether to vote for approval of the merger agreement?

You should review carefully our discussion under “Risk Factors.” You should also review the factors considered by the SBCAB Board in approving the merger agreement. See “Background of and Reasons for the Merger.”

What are the material United States federal income tax consequences of the merger to SBCAB shareholders?

Glacier and SBC expect to reportAB intend for the merger of SBC with and into Glacierto qualify as atax-free reorganization for U.S. federal income tax purposes under “reorganization” within the meaning of Section 368(a) of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”). It is a condition to the closing ofIf the merger that each party receives an opinion from its respective legal counsel that the merger will qualifyqualifies as a reorganization underwithin the meaning of Section 368(a).

In atax-free reorganization, a shareholder who exchanges his, her or its shares of common stock in an acquired company for shares of common stock in an acquiring company, plus cash, must generally recognize gain (but not loss) on the exchange in an amount equal to the lesser of (1) the amount of gain realized (i.e., the excess of the sumInternal Revenue Code, then for U.S. federal income tax purposes a U.S. holder of the fair market value of theAB common shares of the acquiring company(as defined below) generally will not recognize any gain or loss upon surrendering its AB common stock (including any fractional shares) andshares, except with respect to any cash received pursuant toor treated as received in the merger (excludingand any cash received in lieu of fractional shares) over the shareholder’s adjusted tax basisshares. A U.S. holder of AB common shares receiving cash in his, her or its shareslieu of acquired companya fractional share of Glacier common stock surrendered pursuantwill generally recognize gain or loss equal to the merger), or (2)difference between the amount of cash (excluding any cash received instead of a fractional share and the basis in lieuits fractional share of fractional shares) received pursuantGlacier common stock. The U.S. federal income tax consequences described above may not apply to all holders of AB common shares. Your tax consequences will depend on your individual situation. Accordingly, we strongly urge you to consult an independent tax advisor for a full understanding of the merger.

particular tax consequences of the merger to you. For a detailed discussion of the material U.S. federal income tax consequences of the merger, see “The Merger – Material U.S. Federal Income Tax Consequences of the Merger.”

We urge youMerger to consult your tax advisor to fully understand the tax consequences to you of the merger. Tax matters are very complicated and in many cases the tax consequences of the merger will depend upon your particular facts and circumstances.AB Shareholders.”

Do I have appraisal or dissenters’ rights?

Yes. If youNo. Under Utah law, AB shareholders are an SBC shareholder and you do not agreeentitled to exercise appraisal rights in connection with the merger, do not vote in favor of the merger agreement, and take certain other actions required by Arizona law, you will have dissenters’ rights under the Arizona Revised Statutes Sections10-1301 to10-1331.Exercise of these rights will result in the purchase of your shares of SBC common stock at “fair value,” as determined in accordance with Arizona law. If you elect to exercise this right, we encourage you to consult with your financial and legal advisors.merger. Please read the section entitled “The Merger – Dissenters’ Rights”for additional information.

Who can help answer my questions?

If you have questions about the merger, the special shareholders meeting, or your proxy, or if you need additional copies of this document or a proxy card, you should contact:

State Bank Corp.Altabancorp

1771 McCulloch Boulevard1 East Main Street

Lake Havasu City, Arizona 86403American Fork, Utah 84003

ATTN: Karen Gibbs,Attention: Corporate Secretary

Tel. No. (928)Telephone: (801) 302-5165642-3998

RISK FACTORS

In addition to the other information contained in or incorporated by reference into this document, including the matters addressed under the caption “Cautionary Note Regarding Forward-Looking Statements,” you should consider the matters described below carefully in determining whether or not to approve the merger agreement and the transactions contemplated by the merger agreement.

Risks Associated with the Proposed Merger

Because you are receiving a fixed number of shares (subject to adjustment) and the market price of the Glacier common stock may fluctuate, you cannot be sure of the value of the shares of Glacier common stock that you will receive.

At the time of the SBCAB special shareholder meeting, and prior to the closing of the merger, you will not be able to determine the value of the Glacier common stock that you will receive upon completion of the merger. Any change in the market price of Glacier common stock prior to completion of the merger will affect the value of the consideration that SBCAB shareholders will receive in the merger. Common stock price changes may result from a variety of factors, including but not limited to general market and economic conditions, changes in Glacier’s business, operations and prospects, and regulatory considerations. Many of these factors are beyond the control of Glacier or SBC.AB. You should obtain current market prices for Glacier common stock.

The merger agreement provides that the number of shares of Glacier common stock to be issued for each share of SBCAB common stockshare in the merger may be decreased or increased, as the case may be, if the average closing price of Glacier common stock, determined pursuant to the merger agreement, is greater than or less than specified prices. If Glacier’s average closing price determined in accordance with the merger agreement is greater than $47.31$74.15 and Glacier elects to terminate the merger agreement, the SBCAB Board could determine, without resoliciting the vote of SBCAB shareholders, whether or not to accept a decrease on aper-share basis in the number of shares of Glacier common stock to be issued in the merger to avoid such termination. See “The Merger – Termination of the Merger Agreement.”

The results of operations of Glacier after the merger may be affected by factors different from those currently affecting the results of operations of AB.

The businesses of Glacier and AB differ in certain respects and, accordingly, the results of operations of the combined company and the market price of the combined company’s common shares may be affected by factors different from those currently affecting the independent results of operations of AB and Glacier. For a discussion of the business of Glacier and certain factors to be considered in connection with Glacier’s business, see “Information Concerning Glacier” and the documents incorporated by reference in this document and referred to under “Where You Can Find More Information.” For a discussion of the business of AB and certain factors to be considered in connection with AB’s business, see “Information Concerning Altabancorp” and the documents incorporated by reference in this document and referred to under “Where You Can Find More Information.”

The merger agreement limits SBC’sAB’s ability to pursue other transactions and provides for the payment of abreak-up fee if SBCAB does so.

While the merger agreement is in effect, subject to very narrow exceptions, SBCAB and its directors, officers, employees, agents and representatives are prohibited from initiating or encouraging inquiries with respect to alternative acquisition proposals. The prohibition limits SBC’sAB’s ability to seek offers from other potential acquirers that may be superior from a financial point of view to the proposed transaction. If SBCAB receives an unsolicited proposal from a third party that is superior from a financial point of view to that made by Glacier and the merger agreement is terminated, SBCAB will be required to pay a $6,000,000$35,000,000 break-up fee. This fee makes it less likely that a third party will make an alternative acquisition proposal. See “The Merger –Break-Up Fee.”

Combining ourthe two companies may be more challenging, costly or time-consuming than we expect.expected.

Glacier and SBCAB have operated and, until the completion of the merger, will continue to operate, independently. Although Glacier has successfully completed numerous mergers in the recent past, this is a larger transaction than others and regardless it is possible that the integration of the Bank into Glacier Bank could result in the loss of key employees, the disruption of the ongoing business of the Bank or inconsistencies in standards, controls, procedures and policies that adversely affect ourthe Bank’s ability to maintain relationships with customers and employees or to achieve the anticipated benefits of the merger. As with any merger of banking institutions, there also may be disruptions that cause usthe Bank to lose customers or cause customers to take their deposits out of the Bank.

After the merger is completed, SBCAB shareholders will become Glacier shareholders and will have different rights that may be less advantageous than their current rights.

Upon completion of the merger, SBCAB shareholders will become Glacier shareholders. Differences in SBC’sAB’s articles and SBC’sAB’s bylaws and Glacier’s articles and Glacier’s bylaws will result in changes to the rights of SBCAB shareholders who become Glacier shareholders. See “Comparison of Certain Rights of Holders of Glacier and SBCAB Common Stock.Shares.”

SBC’sAB’s shareholders will have a reduced ownership and voting interest after the merger and will exercise less influence over management.

SBC’sAB’s shareholders currently have the right to vote in the election of the SBCAB Board and on other significant matters affecting SBC,AB, such as the proposed merger with Glacier. When the merger occurs, each SBCAB shareholder will become a shareholder of Glacier with a percentage ownership of the combined organization that is much smaller than the shareholder’s percentage ownership of SBC.AB. Based on the anticipated number of Glacier common shares to be issued in the merger, it is anticipated that the SBCAB shareholders will only own approximately 3.4%13.7% of all of the outstanding shares of Glacier’s common stock following the merger. Because of this, SBC’sAB’s shareholders will have less influence on the management and policies of Glacier than they now have on the management and policies of SBC.AB. Furthermore, shareholders of Glacier do not have preemptive or similar rights, and therefore, Glacier can sell additional voting securities in the future without offering them to the former SBCAB shareholders, which would further reduce their ownership percentage in, and voting control over, Glacier.

The merger may fail to qualify as a reorganization for federal tax purposes, resulting in the recognition by SBC’sAB’s shareholders of taxable gain or loss in respect of their SBCAB shares.

Glacier and SBCAB intend the merger to qualify as a reorganization within the meaning of Section 368(a) of the Internal Revenue Code. Glacier and SBC,AB, as a condition to closing, will each obtain an opinion from their respective legal counsel that the merger will qualify as a reorganization for federal tax purposes. These opinions do not bind the Internal Revenue Service or the courts or prevent the Internal Revenue Serviceeither from adoptingtaking a contrary position. Neither Glacier nor SBCAB has requested and neither intends to request any ruling from the Internal Revenue Service as to the U.S. federal income tax consequences of the merger. If the merger fails to qualify as a reorganization, an SBC shareholder generally would recognize gain or loss in an amount equal to the difference between (i) the sum of the amount of cash and the aggregate fair market value of the Glacier common stock received in the exchange, and (ii) the SBC shareholder’s aggregate adjusted tax basis in the SBC common stock surrendered in the exchange. Furthermore, if the merger fails to qualify as a reorganization, Glacier, as successor to SBC,AB, may incur a significant tax liability since the merger would be treated as a taxable sale of SBC’sAB’s assets for U.S. federal income tax purposes.

Glacier and AB will be subject to business uncertainties and contractual restrictions while the merger is pending.

Uncertainty about the effect of the merger on employees, customers and vendors may have an adverse influence on the business, financial condition and results of operations of Glacier and AB. These uncertainties may impair Glacier’s and AB���s ability to attract, retain and motivate key personnel, maintain current deposit levels, and continue to attract depositors and attract new borrowers pending the consummation of the merger, as such personnel, depositors and borrowers may experience uncertainty about their future relationships following the consummation of the merger. Additionally, these uncertainties could cause customers (including depositors and borrowers), suppliers, vendors and others who deal with Glacier or AB to seek to change existing business relationships with Glacier, AB or the combined company or fail to extend an existing relationship with Glacier, AB or the combined company.

In addition, the merger agreement restricts AB from taking certain actions without Glacier’s consent while the merger is pending. These restrictions could have a material adverse effect on AB’s business, financial condition and results of operations. See “The Merger Agreement — Covenants” for a description of the restrictive covenants applicable to AB.

Failure to complete the merger could negatively impact the stock prices and future businesses and financial results of Glacier and SBC.AB.

If the merger is not completed, the ongoing businesses of Glacier and SBCAB may be adversely affected, and Glacier and SBCAB will be subject to several risks, including the following:

Risks Associated with Glacier’s Business

Glacier is, and will continue to be, subject to the risks described in Glacier’s Annual Report on Form10-K for the fiscal year ended December 31, 2018,2020, as updated by aits Quarterly Report on Form10-Q for the quarter ended June 30, 2019,March 31, 2021, and subsequent Current Reports on Form8-K, and Quarterly Reports on Form10-Q, all of which are filed with the SEC and incorporated by reference into this proxy statement/prospectus. See “References to Additional Information” and “Where You Can Find More Information” included elsewhere in this proxy statement/prospectus.

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This document, including information included or incorporated by reference in this document may contain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements include, but are not limited to,to: (i) statements about the benefits of the merger, including future financial and operating results, cost savings, enhancements to revenue and accretion to reported earnings that may be realized from the merger;(ii) statements about our respectiveGlacier’s and AB’s plans, objectives, expectations, intentions, projected financial information, future opportunities and intentions andany other statements regarding Glacier’s and AB’s future expectations, beliefs, plans, objectives, results of operations, financial condition and cash flows that are not historical facts; (iii) the expected timetable for completing the merger; (iv) the ability to complete the merger; and(iii) (v) other statements identified by words such as “expects,” “anticipates,” “intends,” “plans,” “believes,” “seeks,” “estimates,” or words of similar meaning. These forward-looking statements are based on current beliefs and expectations of Glacier’s and AB’s management and are inherently subject to significant business, economic and competitive uncertainties and contingencies, many of which are beyond Glacier’s and SBC’sAB’s control. In addition, these forward-looking statements are subject to assumptions with respect to future business strategies and decisions that are subject to change.

In addition to factors previously disclosed in Glacier’s and AB’s reports filed with the SEC relating to risks to Glacier’s and AB’s business and stock price, and those identified elsewhere in this document (including the section entitled “Risk Factors”), the following potential factors, among others, could cause actual results to differ materially from the anticipated results or other expectations expressed or implied in the forward-looking statements:

The foregoing list of factors is not intended to be exhaustive. These forward-looking statements reflect Glacier’s and AB’s current views with respect to future events and are based on numerous assumptions and assessments made by Glacier and AB in light of their experiences and perceptions of historical trends, current conditions, business strategies, operating environments, future developments and other factors they believe appropriate. By their nature, forward-looking statements involve known and unknown risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. The factors described in the context of such forward-looking statements in this document could cause Glacier’s and AB’s plans with respect to the merger, actual results, performance or achievements, industry results and developments to differ materially from those expressed in or implied by such forward-looking statements. Although it is believed that the expectations reflected in such forward-looking statements are reasonable, no assurance can be given that such expectations will prove to have been correct and persons reading this document are therefore cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this proxy statement/prospectus or, in the case of a document incorporated by reference, as of the date of that document. All subsequent written and oral forward-looking statements concerning the proposed transaction or other matters attributable to Glacier or SBCAB or any person acting on behalf of Glacier or SBCAB are expressly qualified in their entirety by the cautionary statements above. Neither Glacier nor SBCAB undertakes any obligation to update any forward-looking statements to reflect circumstances or events that occur after the date the forward-looking statements are made.

SELECTED HISTORICAL FINANCIAL INFORMATION OF GLACIER

The following table presents selected consolidated financial information of Glacier for the periods and dates indicated. This information has been derived from Glacier’s consolidated financial statements filed with the SEC. Historical data as of and for the six months ended June 30, 2019 and 2018 are based upon unaudited financial statements and include, in the opinion of Glacier management, all normal recurring adjustments considered necessary to present fairly the results of operations and financial condition of Glacier. The consolidated financial data below should be read in conjunction with the consolidated financial statements and notes thereto, incorporated by reference in this proxy statement/prospectus. See “Where You Can Find More Information.”

SBCAB SPECIAL SHAREHOLDERS’ MEETING

Date, Time, Place

The SBCAB special meeting of shareholders will be held on [][___], 2019,2021, at [] [].m.[___] Mountain StandardTime. The special meeting will be held in virtual meeting format only. In order to attend the special meeting, AB shareholders must register at www.proxydocs.com/ALTA by 5:00 p.m. Mountain Time at []on [__], Lake Havasu City, Arizona.2021.

As described below under the “Votes Required and Quorum,” approval of the merger agreement requires the affirmative vote of at least a majority of the outstanding shares of SBC’sAB’s common stock entitled to vote on the matter. The proposal to approve merger-related compensation to named executives on an advisory basis will be approved if the votes cast in favor of the proposal exceed the votes cast opposing the proposal, assuming a quorum is present. The proposal to adjourn the special meeting, if necessary or appropriate, including adjournments to solicit additional proxies, will be approved if approved by a majoritythe votes cast in favor of the voting power present,proposal exceed the votes cast opposing the proposal, whether in person or by proxy, assumingnot a quorum is present.

Purpose

At the special meeting, SBCAB shareholders will:

Record Date; Shares Outstanding and Entitled to Vote

The SBCAB Board has fixed the close of business on [][___], 20192021, as the record date for determining the holders of shares of SBCAB common stockshares entitled to notice of and to vote at the special meeting. At the close of business on the record date, there were approximately [][___] holders of record and [][___] AB common shares of SBC common stock issued and outstanding, excluding [] shares of unvested restricted stock, which do not have voting rights.outstanding. Holders of record of SBCAB common stock, excluding unvested restricted shares on the record date are entitled to one vote per share and are also entitled to exercise dissenters’ rights if certain procedures are followed. See “The Merger – Dissenters’ Rights” andAppendix B.share. Unvested RSUs do not have voting rights.

SBC’sAB’s directors and executive officers and certain significant shareholders have agreed to vote all shares of SBCAB common stockshares they are entitled to vote that are held or controlled by them in favor of approval of the merger agreement. As of the record date, a total of [][_________] AB common shares, of SBC common stock, representing approximately [][____]% of all outstanding shares of SBCAB common stock, excluding shares of unvested restricted stock, are subject to voting agreements. See “The Merger – Interests of SBC Directors and Executive Officers in the Merger – Voting Agreements.”Agreements”.

Votes Required and Quorum

The affirmative vote of the holders of at least a majority of the outstanding shares of SBC’sAB’s common stock entitled to vote is required to approve the merger agreement. At least a majority of the total outstanding shares of SBCAB common stockshares entitled to vote must be present, either in personat the meeting or by proxy, in order to constitute a quorum for the special meeting. For purposes of determining a quorum, abstentions and brokernon-votes will be counted in determining the shares present at a meeting.

With respect to the merger-related named executive compensation proposal, approval of such proposal requires that the votes cast in favor of the proposal exceed the votes cast opposing the proposal. As a result, abstentions and broker non-votes with respect to the merger-related named executive officer compensation proposal will have no effect on the merger-related named executive officer compensation proposal.

With respect to the proposal to adjourn the special meeting if necessary or appropriate, if a quorum is not present at the special meeting, shareholders entitled to vote at the special meeting, present in personat the meeting or by proxy, will have the power to adjourn the special meeting. If a quorum is present at the special meeting, the proposal to adjourn the special meeting, if necessary or appropriate, including an adjournment to solicit additional proxies in favor of the merger agreement, will be approved if approved by a majoritythe votes cast in favor of the voting power present atproposal exceed the special meeting, whether in person or by proxy.votes cast opposing the proposal.

Voting, Solicitation, and Revocation of Proxies

If you are a holder of record of SBCAB common stockshares as of the record date for the special meeting, there are four ways to have your shares voted:

If the enclosed proxy card is duly executed and received in time for the special meeting, it will be voted in accordance with the instructions given. If the proxy card is duly executed and received but no instructions are given, it is the intention of the persons named in the proxy to vote the shares represented by the proxyFOR the approval of the merger agreement, FOR the proposal to approve merger-related compensation of AB’s named executive officers andFOR the proposal to approve one or more adjournments to solicit additional proxies, and in the proxy holder’s discretion on any other matter properly coming before the meeting. Any proxy given by a shareholder may be revoked before its exercise by:

SBCAB is soliciting the proxy for the special meeting on behalf of the SBCAB Board. SBCAB will bear the cost of solicitation of proxies from its shareholders. In addition to using the mail, SBCAB may solicit proxies by personal interview, telephone, and facsimile. Banks, brokerage houses, other institutions, nominees, and fiduciaries will be requested to forward their proxy soliciting material to their principals and obtain authorization for the execution of proxies. SBCAB will, upon request, pay the standard charges and expenses of banks, brokerage houses, other institutions, nominees, and fiduciaries for forwarding proxy materials to and obtaining proxies from their principals.

Voting in Person at the Special Meeting

Shares helddirectly in your name as the shareholder of record may be voted in person atduring the special meeting. If you choose to vote your shares of SBC common stock in person, please bringmeeting by following the enclosed proxy card or proof of identification.instructions available on the meeting website. Even if you plan to attendparticipate at the virtual special

meeting, we recommendAB recommends that you vote your shares of SBCAB common stockshares in advance as described above so that your vote will be counted if you later decide not to attend the special meeting.

If your shares are registered in “street name” in the name of a broker or other nominee and you wish to vote atduring the special meeting, you will need to obtain a legal proxy from your bank or brokerage firm. Please consult the voting form sent to you by your bank or broker to determine how to obtain a legal proxy in order to vote in person at the meeting.

The AB Proposals

Proposal 1: Merger Proposal

AB is asking its shareholders to approve the merger agreement. For a detailed discussion of the terms and conditions of the merger agreement, please see the section entitled “The Merger.” AB shareholders should read this proxy statement/prospectus, including any documents incorporated in this proxy statement/prospectus by reference, and its annexes, carefully and in their entirety for more detailed information concerning the merger agreement and the merger. A copy of the merger agreement is attached to this proxy statement/prospectus as Appendix A.

As discussed in the section entitled “Background of and Reasons for the Merger,” after careful consideration, the AB Board approved the execution, delivery and performance of the merger agreement and the transactions contemplated by it, including the merger, and determined the merger to be fair and in the best interests of AB and the AB shareholders.

Required Vote

Approval of the proposal to approve the merger agreement requires the affirmative vote of at least a majority of the outstanding shares of AB’s common stock entitled to vote. If you mark “ABSTAIN” on your proxy card, fail to submit a proxy card or fail to vote by mail, by telephone, via the Internet, or via remote participation through the virtual format of the meeting at the AB special meeting, or are a “street name” holder and fail to instruct your bank, broker, or other nominee how to vote, it will have the same effect as votes against the merger proposal.

The approval of the merger by holders of AB common shares is a condition to the completion of the merger.

The AB Board recommends that AB shareholders vote “FOR” the proposal to approve the merger agreement.

Proposal 2: Advisory Proposal to Approve Merger-Related Named Executive Officer Compensation

Pursuant to Section 14A of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), AB is providing its shareholders with the opportunity to cast an advisory (non-binding) vote to approve the compensation that may be paid or become payable to its named executive officers that is based on or otherwise relates to the merger, as disclosed in the section entitled “The Merger—Interests of AB Directors and Executive Officers in the Merger.” As required by Section 14A of the Exchange Act, AB is asking its shareholders to vote to adopt the following resolution:

“RESOLVED, that the compensation that may be paid or become payable to AB’s named executive officers that is based on or otherwise relates to the merger, and the agreements or understandings pursuant to which such compensation may be paid or become payable, in each case as disclosed pursuant to Item 402(t) of Regulation S-K in the section of the proxy statement/prospectus statement entitled “The Merger—Merger-Related Compensation for AB’s Named Executive Officers”, are hereby APPROVED.”

Required Vote

Approval of the advisory proposal to approve merger-related named executive officer compensation requires that the number of votes cast in favor of the proposal exceed the votes cast opposing the proposal,

assuming a quorum is present. If you mark “ABSTAIN” on your proxy card, fail to submit a proxy card or fail to vote by mail, by telephone, via the Internet, or via remote participation through the virtual format of the meeting at the AB special meeting, or are a “street name” holder and fail to instruct your bank, broker, or other nominee how to vote, it will have no effect on the merger-related named executive officer compensation proposal.

The vote to approve the merger-related named executive officer compensation proposal is a vote separate and apart from the vote to approve the merger agreement. Accordingly, a shareholder may vote to approve the merger-related named executive officer compensation proposal and vote not to approve the merger agreement or vice versa. Because the merger-related named executive officer compensation proposal vote is advisory only, it will not be binding on the parties to the merger. If the merger is completed, the merger-related named executive officer compensation subject to the merger-related named executive officer compensation proposal will be paid to AB’s named executive officers to the extent payable in accordance with the terms of the applicable compensation agreements and arrangements even if holders of AB common shares fail to approve the merger-related named executive officer compensation proposal.

The approval of the merger-related named executive officer compensation proposal is not a condition to the completion of the merger.

The AB Board recommends a vote “FOR” the proposal to approve merger-related compensation of AB’s named executive officers.

Proposal 3: Adjournment Proposal

AB is asking its shareholders to approve the adjournment of the AB special meeting to another date and place if necessary or appropriate to solicit additional votes in favor of the merger proposal if there are insufficient votes at the time of such adjournment to approve the merger proposal.

If, at the AB special meeting, an insufficient number of AB common shares are present via remote participation through the virtual format of the meeting or represented by proxy and voting in favor of the merger proposal, AB will move to adjourn the AB special meeting to enable the AB Board to solicit additional proxies for approval of the merger proposal. If the AB shareholders approve the adjournment proposal, AB may adjourn the AB special meeting and use the additional time to solicit additional proxies, including the solicitation of proxies from AB shareholders who have previously voted. If the date of the adjournment is not announced at the AB special meeting or a new record date is fixed for the adjourned meeting, a new notice of the adjourned meeting will be given to each shareholder of record entitled to vote at the adjourned meeting.

Required Vote

Approval of the adjournment proposal requires that the number of votes cast in favor of the proposal exceed the votes cast opposing the proposal, whether or not a quorum is present. If you mark “ABSTAIN” on your proxy card, fail to submit a proxy card or fail to vote by mail, by telephone, via the Internet, or via remote participation through the virtual format of the meeting at the AB special meeting, or are a “street name” holder and fail to instruct your bank, broker, or other nominee how to vote, it will have no effect on the adjournment proposal.

The AB Board recommends that AB shareholders vote “FOR” the adjournment proposal.

Other Matters to Come Before the AB Special Meeting

As of the date of this proxy statement/prospectus, the AB Board is not aware of any matters that will be presented for consideration at the AB special meeting other than as described in this proxy statement/prospectus. If, however, the AB Board properly brings any other matters before the AB special meeting, the persons named in the proxy will vote the shares represented thereby in accordance with the recommendation of the AB Board on any such matter.

BACKGROUND OF AND REASONS FOR THE MERGER

Background of the Merger

As partThe AB Board, with the assistance of its ongoing considerationexecutive management, periodically reviews, assesses, and evaluation of SBC’s long-term prospectsdiscusses AB’s strategic direction, performance, and strategy, SBC’s Board of Directorsprospects. These reviews and senior managementdiscussions have periodically reviewedincluded from time to time, third party advisors, including investment bankers and assessedexternal legal counsel, and have addressed the potential strategic alternatives that might be available to AB, including organic growth opportunities, and challenges. The Board of Directors has considered the prospects of continued growth and operating a financial institution under current economic, regulatory and competitive conditions. At the same time, like many other smaller financial institutions, SBC has experienced increasing costs related to technology and regulatory compliance.

As part of the Board of Directors’ and management’s evaluation of ways to meet these challenges, they have met regularly with Davidson to review developments in the banking industry and the equity markets generally, thepotential mergers and acquisitions market, SBC’s financial performance relative to certain other financial institutions, capital management strategies and valuation trends. Davidson is a nationally recognized investment banking firm with substantial experience advising financial institutions generally, including with respect to mergers and acquisitions.

On July 9, 2018, the SBC Board held a meeting to evaluate a potential strategy for SBC to complete an initial public offering (“IPO”). Davidson and Hogan Lovells US LLP, SBC’s outside legal counsel (“Hogan”), also attended the meeting. The meeting included discussion regarding the requirements for being a public company, as well as the benefits and costs to be incurred if SBC decided to pursue an IPO strategy.

On November 29, 2018, the SBC Board held a strategic meeting as part of the Board’s ongoing assessment of SBC’s strategic opportunities and challenges. Representatives of Davidson and Hogan also attended the meeting. At the meeting, Hogan reviewed strategic planning guidelines and an overview of director responsibilities and conduct during the strategic planning process, and the Board reviewed and discussed with Hogan the Board’s fiduciary duties in a merger context. Davidson discussed with the Board developments in the banking industry, an update on the equity markets as well as valuations for peer financial institutions and other financial institutions in general, the mergers and acquisition market and current valuation metrics. The discussion also included SBC’s desire to evaluate(including potential acquisition targets and the limited numbersale of viableAB), and capital planning decisions, all with the goal of enhancing shareholder value. These reviews and discussions have also included analyses of the business environment for financial institutions, including technology initiatives and investments, the impact of low interest rates, the evolution of community banking, and talent acquisition targets remaining for SBC, especiallyand retention. Economic outlook nationally and locally, the regulatory and compliance environment, financial institution industry trends, peer comparisons, ongoing consolidation among financial institutions, and the benefits and risks of continued operation as a standalone company have also been considered. Factors assessed in Arizona. Davidson also reviewedconnection with these reviews have included the mergerrisks and acquisition processopportunities associated with operating in existing and new markets, competition, potential positive and negative expense and revenue synergies, regulatory requirements, interest rate environment and prospects, scale, operational risk, credit risk, market risk, and changes in technology and in delivery and marketing channels. In connection with the evaluation of strategic alternatives, AB’s executive management has had, from time to time, informal discussions, including regarding potential acquisitions or the sale of AB, with representatives of other merger considerations, including a listfinancial institutions and has regularly updated the AB Board regarding such discussions.

Randall M. Chesler, President and Chief Executive Officer of potential strategic partners for SBC, which such list included Glacier. The SBC Board authorized Brian Riley to contact three parties, including Glacier, and Parties ALen E. Williams, President and B,Chief Executive Officer of AB, have lengthy careers in the financial institutions industry and have known each other professionally for the last two to discussthree years since Mr. Williams joined AB. Messrs. Chesler and Williams have periodically informally discussed matters of mutual interest to their respective institutions, and Mr. Chesler inquired on at least one occasion about a potential business combination.

Certain members of the possibility ofGunther family and their related entities (the “Section 13D Group”) executed a mergershareholder agreement on January 28, 2020 and execute an NDAjointly filed a Schedule 13D with the parties.Securities & Exchange Commission on June 12, 2020. At the time, two of the 10 members of the AB Board were part of the Section 13D Group.

On December 5, 2018, Brian Riley contactedTo avoid potential conflicts of interest and to advance the CEObest interests of the company and its shareholders, in July of 2020, all 10 members of the AB Board unanimously voted to establish a special committee comprising all directors other than the directors that were members of the Section 13D Group to act on behalf of the company with respect to considering and responding to the goals and requests of the Section 13D Group.

In August 2020, the AB Board convened its regularly scheduled annual two-day retreat to review, assess, and set the company’s strategic direction. As is customary practice, the AB Board, with the assistance of executive management, considered and set various key strategic objectives for the company. In addition, the AB Board and executive management considered and discussed the contents and potential impacts of the Schedule 13D filing by the Section 13D Group. After considering the positive performance trajectory of the company, the successful implementation of technology initiatives, and the experience and capabilities of executive management, among other factors, the AB Board adopted and endorsed the strategic direction for the company, including to remain independent and pursue organic growth and potential acquisition opportunities.

In November 2020, executive management presented an opportunity to acquire a bank outside of the state of Utah. The AB Board unanimously directed executive management to begin formal discussions with Party A. The parties executed a nondisclosure agreement on December 21, 2018, and Party A was provided with access to certain confidential information for due diligence.

On December 12, 2018, Brian Riley contacted Glacier’s CEO. Mr. Riley previously met with Glacier’s CEO and Senior Executives in May of 2017 and September of 2018 to discussX regarding a potential strategic partnership. The parties decided to schedule a meeting in Kalispell, Montana for January 14, 2019, to further discuss a potential merger betweenacquisition.

During the two companies. At this meeting, Glacier described interest in merger discussions, but could not announce a transactioncourse of the next several months, at regularly-scheduled Board meetings and through periodic communications with SBC until the fourth quarter 2019, since Glacier was workingAB Board, executive management provided the AB Board updates on other pending acquisition opportunities which had not been publicly announced. The parties agreed to postpone further discussions on a merger until the summer of 2019.unsolicited

contacts and inquiries from third parties regarding a possible sale of the company, including unsolicited approaches from Glacier and Party B, key metrics on the company’s strategic direction adopted at the AB Board’s annual retreat, and progress on various potential acquisition opportunities.

On January 29, 2019, Davidson received11, 2021, the AB Board unanimously approved the submission of anon-binding indicationletter of interest fromto Party AX regarding the acquisition of Party X by AB.

On January 15, 2021, Paul Gunther, a member of the Section 13D Group, resigned as a director of AB.

At a special meeting convened on January 15, 2021, the AB Board considered and discussed the strategic objectives of the company. Mr. Williams also provided an update to the AB Board on potential acquisition opportunities. In addition, the AB Board considered and discussed the amended Schedule 13D filed by the Section 13D Group on January 14, 2021, which included a letter to the AB Board requesting that the AB Board review strategic alternatives for 100% stock consideration.AB, including a potential sale of the company. The SBCfiling also noted the 13D Group’s objection to AB acquiring another bank and its concern that the current Board heldof Directors and executive management would be incapable of successfully executing such a transaction. Keefe, Bruyette & Woods, Inc., acting as financial advisor to AB (“KBW”), was invited to the meeting to discuss with the AB Board the potential process for undertaking a review of the company’s strategic alternatives and how KBW could assist in that review.

At its regularly-scheduled meeting on January 31, 2019,26, 2021, the AB Board received a presentation from Jones Day, legal counsel to AB, regarding the directors’ fiduciary duties under applicable law and related obligations in reviewing and considering strategic alternatives, which was followed by review the offer from Party A, along with Davidson and Hogan in attendance. After evaluating the offer, and discussing with Davidson and Hogan, the Board decided it would not pursue further discussion with KBW of strategic considerations and the following alternatives: (i) remain standalone/independent; (ii) pursue mergers and acquisitions; (iii) explore a merger of equals; or (iv) undertake a controlled sale process. The market landscape, potential targets, prospective buyers, valuation considerations, and related financial considerations were reviewed and discussed. The AB Board met in executive session to discuss the foregoing, after which the AB Board voted unanimously to continue with the strategic direction previously agreed to in August 2020 at the AB Board’s annual retreat, mainly to remain as an independent entity and pursue potential acquisition opportunities, including the potential acquisition of Party A sinceX.

On January 27, 2021, the consideration value was below SBC’s expectationsSection 13D Group filed an amended Schedule 13D, which included a letter to the AB Board, reiterating the Section 13D Group’s request that AB review strategic alternatives, including a potential sale of the company.

On February 1, 2021, Jonathan Gunther, a member of the Section 13D Group, resigned as a director of AB.

At a special meeting convened on February 11, 2021, The AB Board considered recent developments, including the ongoing consolidation among financial institutions, executive management’s ongoing discussions regarding a potential acquisition opportunity, and more broader concerns with recent volatilitythe significant potential costs likely to be incurred by AB and the potential disruption to AB’s business in the stock market and impact on Party A’s stock price. Party A was notified and discussions were suspended on February 5, 2019.

On November 14, 2018, Brian Riley met with Party B for an informal discussion on general banking matters. In March and April 2019, SBC had communications with the CEO of Party B and revisited the ideaevent of a proxy contest. The AB Board discussed the company’s strategic merger combination. SBCalternatives in light of these developments and Party B executed a nondisclosure agreement on April 26, 2019. Party B was provided with accesshow best to certain confidential informationfurther validate the best future strategy for due diligence.

On May 2, 2019, SBC executed an engagement letter with Davidson.

On May 7, 2019, Brian Riley and Glacier’s CEO held a discussion while attending the Davidson annual financial institutions conference.AB. The parties discussed continuedAB Board determined to direct KBW to (i) approach prospective buyers to solicit interest in a mergerpossible sale of the company and Glacier provided an updatealso (ii) to concurrently continue to move forward with a potential acquisition of Party X.

At the direction of the AB Board, on timingFebruary 16, 2021 executive management, with the assistance of KBW, commenced the solicitation process for a possible sale of AB. Continuing over the course of several days, representatives of KBW contacted or were contacted by potential transactioncounterparties, including Glacier. With KBW’s assistance, the AB Board and executive management identified potential buyers of AB with (i) the greatest financial ability to begin due diligence in July or August 2019, with an announcement in fourth quarterpay (based on their relative buying power versus third parties, as determined based on publicly available information) and (ii) a similar strategic direction and culture as AB. Each of 2019. On May 17, 2019, Glacier and SBC executed a nondisclosure agreement.

On May 7, 2019, Brian Riley and Party B’s CEO held a discussion while attending the Davidson annual financial institutions conference. The parties discussed continued interest in a merger, preliminary due diligence and timing for next steps.

On May 23, 2019, SBC received anon-binding indication of interest letter from Party B for 100% stock consideration. The offer also included a90-day period of exclusivity with Party B. The SBC Board held a meeting on May 30, 2019, to review the offer from Party B, with Davidson and Hogan in attendance. The SBC Board discussed the offer, and noted the SBC shareholders would retain a sizeable ownership percentage in the pro forma company. The SBC Board authorized Brian Riley and Davidson to continue negotiations with Party B.

On June 6, 2019, SBC and Party B executed a nonbinding indication of interest letter which included a45-day exclusivity period and provided for two (2) of SBC’s directors to join Party B’s Board of Directors. Subsequently, Party B and SBC immediately began due diligence and reverse due diligence, where confidential information was exchanged between the parties. As due diligence continued, SBC management expressed concerns about the integration risk and execution risk with Party B. The SBC Board discussed these concerns at the June 27, 2019, board meeting, but decided to continue its due diligence. SBC and Party B held anin-person meeting for due diligence in early July 2019 with representatives from Davidson and Hogan in attendance. Subsequent to this meeting, the SBC Board held a telephonic meeting to discuss the integration risk and execution risk and voted that it was no longer in the best interest of SBC shareholders to continue pursuing a merger with Party B.

On July 5, 2019, Brian Riley notified Party B that the SBC Board decided to terminate discussions with Party B, but SBC would honor the exclusivity period as agreed upon, which continued through July 21, 2019.

On June 18, 2019, Glacier contacted SBC to inform SBC the timing for anine potential merger could be moved up. Davidson and SBC responded to Glacier that SBC had executed an indication of interest with another party and was precluded to respond further due to the exclusivity period currently in effect.

counterparties received initial marketing information and draft non-disclosure agreements. Ultimately, seven of those parties expressed interest in the potential acquisition of AB, executed customary non-disclosure agreements, received preliminary due diligence information, and received a process letter requesting indications of interest by March 12, 2021. Of the parties that executed a non-disclosure agreement, four parties elected to receive a management presentation and meeting.

At its regularly-scheduled meeting on February 24, 2021, the AB Board received an update from KBW regarding the sale process, including preliminary due diligence performed by interested counterparties, and the anticipated timeline for indications of interest, as well as an update from executive management on the company’s concurrent pursuit of a potential acquisition of Party X.

During the period from March 2, 2021 to March 5, 2021, AB conducted management presentations and meetings with Glacier, Party A, Party B, and Party C.

On July 9, 2019,March 8, 2021, Glacier’s executive management team and D.A. Davidson & Co., financial advisor to Glacier sent an unsolicited nonbinding indication(“D.A. Davidson”), met with the Glacier board of directors to discuss the pro forma financial modeling and approach to submitting a letter of intent later in the week. D.A. Davidson also discussed pricing strategies based on other interested banks’ ability to pay, as well as Glacier’s pricing differentiation versus the other banks needed to encourage AB to conclude the process in one round and move forward with Glacier.

At a special meeting convened on March 15, 2021, KBW reviewed with the AB Board the process undertaken to date by AB, with KBW’s assistance, in respect of a potential sale of the company. AB received indications of interest to SBC,acquire AB from (i) Glacier indicating an all-stock proposal (with the potential for a special cash dividend based on the amount of AB capital and certain other amounts at closing) at a fixed exchange ratio of 0.7971 shares of Glacier common stock for each AB common share, which (excluding any special cash dividend) represented an implied per share value of approximately $53.01 per share and an implied 37.2% premium to AB’s stock price at such time, (ii) Party A indicating an all-stock offer at a fixed exchange ratio which represented an implied per share value of approximately $48.58 per share and an implied 25.8% premium to AB’s stock price at such time, (iii) Party B indicating an all-stock offer at a fixed exchange ratio which represented an implied per share value of approximately $43.62 per share and an implied 12.9% premium to AB’s stock price at such time, and (iv) Party C indicating an all-stock offer (though Party C expressed a willingness to discuss a mix of cash and stock) at a fixed exchange ratio which represented an implied per share value of approximately $42.73 per share and an implied 10.6% premium to AB’s stock price at such time. In order to present all of the indications of interest on a per share dollar basis, certain assumptions regarding AB’s share count, AB’s share price, and the share price of the applicable potential counterparty were made. The AB Board discussed and reviewed each of the indications of interest with AB’s executive management, KBW, and Jones Day. The AB Board, with input received from management and its external advisors, discussed (i) that the Glacier proposal was more than 9% higher than the next highest proposal received from Party A, (ii) the low prospect that a superior bid could be found because (x) potential counterparties identified by AB, with KBW’s assistance, were selected on the basis of the greatest financial ability to pay (based on their relative buying power versus third parties, as determined based on publicly available information) and (y) the 37.2% premium to AB’s stock price at such time (excluding any special cash dividend) was higher than the significant majority of the previously announced bank M&A transactions reviewed with the AB Board by KBW, and (iii) that Glacier has successfully completed over a dozen acquisitions of similar banks on a set of terms and conditions that were substantially similar to one another. The AB Board considered the possibility of seeking to further negotiate the stock consideration offered by the various bidders but in light of the prices proposed and ability of each bidder to pay, the AB Board ultimately concluded that it was more advisable to proceed with the transaction proposed by Glacier. Jones Day advised the AB Board regarding their fiduciary duties under applicable law. The AB Board then unanimously voted to authorize management of the company to proceed to pursue and negotiate a business combination transaction with Glacier and to discontinue discussions regarding a potential acquisition of Party X.

Also on March 15, 2021, the Section 13D Group filed an amended Schedule 13D, which included per share considerationa letter to AB’s shareholders, announcing the Section 13D group’s intention to consider a “vote no” campaign against certain of 80% inAB’s directors.

KBW informed Glacier stockof the AB Board’s decision to pursue and 20% in cash, plusnegotiate a business combination transaction with Glacier on March 16, 2021. Executive management representatives of Glacier and AB negotiated and discussed additional cash for a dividend prior to closing. After SBCdeal terms within the parameters discussed with Hoganthe AB Board over the course of the next several business days, including, without limitation, the amount of Glacier’s requested termination fee and Davidson, SBC instructed Davidson to inform Glacier that SBC received the letter, but SBC was bound toduration of the exclusivity period withto be granted to Glacier for purposes of negotiating a definitive agreement. On March 18, 2021, the other party, and will not discuss anything further with Glacier until the exclusivity period expired.

On July 11, 2019, Hogan sentparties executed a letter of intent.

Commencing March 22, 2021 and continuing through May 18, 2021, Messrs. Chesler and Williams and other executive management representatives from Glacier and AB, respectively, had periodic telephonic meetings to inform Party B, as required bydiscuss and negotiate the terms of the exclusivitymerger and potential integration. During this period, Glacier performed extensive diligence of AB, and AB, in turn, undertook reverse diligence of Glacier during this time period. During the indication of interest between Party B and SBC, that SBC received an unsolicited indication of interestdiligence process, various working groups from a third party (Glacier) for an acquisition of SBC, but would honor the exclusivity period..

On July 21, 2019, the exclusivity period with Party B expired.

On July 22, 2019, SBC contacted Glacier and informed them that SBC wouldAB, including information technology, accounting, retail operations, legal and compliance, credit, human resources, marketing, internal audit, data warehouse, and commercial banking, met virtually to exchange information and discuss the Glacier offer atproposed transaction. Representatives of KBW and D.A. Davidson also attended many of these meetings.

At the regularly scheduled SBCregularly-scheduled AB Board meeting on July 30, 2019.

On July 30, 2019,March 31, 2021, Mr. Williams provided the SBCAB Board reviewed the nonbinding indication of interest from Glacier with Davidson and Hogan representatives in attendance. Davidson provided an update regarding the proposed merger transaction, including the status of due diligence and various potential integration matters. The potential negative impact of the mergers and acquisitions market and recent trendsdecline in merger market metrics for financial institutions, and discussed recent transactions involving peer institutions, the financial terms of the indication of interest from Glacier in comparison to those metrics and in comparison to the expected future performance of SBC based upon information and projections provided by management. The Board reviewed the process and timeline that would occur if the Board determined to proceed with a merger. Davidson then reviewed in detail the indication of interest from Glacier, and Glacier’s history and recent financial performance and trading metrics. The SBC Board discussed the pricing offered,stock price, as well as Glacier’s intentionthe interest rate effect on the fair valuation of investment securities available for sale and the corresponding recording of the unrealized gain or loss to remain committedshareholders’ equity, on the transaction’s economics were discussed. A special meeting of the AB Board was convened on April 1, 2021 to community banking in Arizona, Glacier’s model for operating banking divisionsdiscuss the transaction’s economics further. After consultation with and its desire for Brian Rileyinput from executive management, Jones Day, and KBW, the AB Board directed executive management of the company to serve as Presidentmove forward with due diligence and CEOKBW and executive management of Glacier’s Arizona division, with the expectation thatcompany to continue to monitor closely the business structure would limit disruption to SBC’s business and have a limited impact on SBC’s employees, customers and communities. After considering Glacier’s proposal, the SBC Board indicated it was interested in a merger with Glacier, and instructed Davidson to respond to Glacier. Between July 31 and August 10, 2019, SBC and Glacier, with the assistance of their respectivetransaction economics.

On April 16, 2021, Miller Nash LLP, legal counsel and financial advisors, negotiated several aspects of Glacier’s indication of interest.

SBCto Glacier (“Miller Nash”), provided Glacier with updated financial results including the second quarter of 2019 and based on this information, Glacier submitted an updated indication of interest on August 10, 2019, which included a modified and improved offer for merger consideration of $16.94 per share in the form of 90% stock and 10% cash, plus potential additional cash for a closing dividend for SBC’s excess capital at closing, subject to adjustment. SBC held a special Board meeting on August 12, 2019 to review Glacier’s latest proposal and the SBC Board voted unanimously to execute the nonbinding indication of interest with Glacier, which provided Glacier with exclusivity for a period of 60 days.

On August 29, 2019, Glacier’s counsel provided SBC’s counsel with an initial draft of the merger agreement. Glacier, SBCBetween that receipt date and their respective legal counselMay 14, 2021, Miller Nash and financial advisors conducted due diligence and drafted and negotiatedJones Day exchanged drafts of the merger agreement and related ancillaryother transaction documents, including voting agreements through September 27, 2019.

Beginning September 9, 2019, SBCto be entered into by each of the directors and Davidson conducted documenteach of the executive officers of AB and certain other shareholders of AB and non-compete/non-solicitation agreements to be entered into by each of the directors. The two law firms and the respective management teams negotiated, exchanged drafts, and worked towards finalizing the terms and conditions of the merger agreement, the voting agreements and other transaction documents. AB negotiated with Glacier to obtain more favorable terms and conditions in the merger agreement. Reciprocal due diligence on Glacier. On September 18, 2019, representatives from SBC, Davidson, Hogan, Glacier and KBW participated incontinued during this time period as well.

At the April 28, 2021 regularly-scheduled AB Board meeting, Mr. Williams provided the AB Board a reversedetailed update regarding the proposed merger transaction, including the status of due diligence, conference callnegotiation of the merger agreement, and various operational and integration matters. With participation from Jones Day, the AB Board reviewed and discussed the negotiation of key terms of the draft merger agreement, proposed voting agreements for executive officers and directors, and proposed non-compete/non-solicitation agreements for directors. The AB Board considered the governance structure of Glacier, including its board of directors as well as its divisional board structure. The AB Board discussed a proposed timeline for completing negotiation and anticipated next steps and directed KBW to provide informationmeet with D.A. Davidson and Glacier regarding the transaction and the impact of the recent decline in Glacier’s stock price, as well as the interest rate effect on the fair valuation of investment securities available for sale and the corresponding recording of the unrealized gain or loss to SBC regarding Glacier and answer questions from SBC and Davidson.shareholders’ equity.

On September 19, 2019,May 10, 2021, a special meeting of the SBCAB Board togetherwas convened. KBW updated the AB Board on its discussion with Glacier and D.A. Davidson about the transaction’s economics. Jones Day addressed the status of the legal documentation for the proposed transaction. The proposed timing and strategy for approaching the Section 13D Group regarding the proposed transaction was also discussed. The Board discussed the overall strength and viability of the proposed transaction, taking into account the fluctuation in the implied valuation as a result of changes in stock prices, and the AB Board instructed executive management of AB to continue to move forward negotiating the potential transaction with the assistance of AB’s external advisors. The AB Board also authorized executive management and the advisors of AB to contact Davis Partnership, L.P., Davis Capital Partners, LLC and Lansing Davis (collectively, the “Davis Group”) and representatives for the Section 13D Group in connection with the potential transaction.

Also on May 10, 2021, Mr. Williams approached the Davis Group regarding execution of a customary non-disclosure agreement to facilitate discussion about the potential transaction and garnering the group’s support for the same through execution of a voting agreement.

On May 11, 2021, the Davis Group entered into a non-disclosure agreement.

On or about May 11, 2021, as directed by the AB Board, KBW and Jones Day approached the investment banker and legal counsel, respectively, for the Section 13D Group regarding execution of a customary non-disclosure agreement to facilitate discussion about the potential transaction and garnering the group’s support for the same through execution of a voting agreement.

On May 12, 2021, the Section 13D Group entered into a non-disclosure agreement with AB, after which KBW and Jones Day discussed with the Section 13D Group’s advisors the general terms of the proposed transaction and the request for execution of a voting agreement. During the period from May 12, 2021 to May 17, 2021, legal counsel to the Section 13D Group, Miller Nash, Jones Day, and executive management of AB negotiated and exchanged drafts of the voting agreement.

Also on May 12, 2021, Mr. Williams discussed the potential transaction and the voting agreement with the Davis Group. During the period between May 12, 2021 and May 17, 2021, legal counsel to the Davis Group, Miller Nash, Jones Day and management of AB negotiated and exchanged drafts of the voting agreement.

Also on May 12, 2021, certain executive officers of AB were presented with draft employment agreements to be entered into in connection with the signing of the merger agreement. During the period from May 12, 2021 to May 16, 2021, Miller Nash and certain executive officers of AB and their independent counsel negotiated and exchanged drafts of the employment agreements.

On May 17, 2021, at the Section 13D Group’s request, Mr. Chesler, Craig A. Langel, chair of Glacier’s Board of Directors, Ronald J. Copher, Executive Vice President and Chief Financial Officer of Glacier, and Donald J. Chery, Executive Vice President and Chief Administrative Officer of Glacier, met with representatives of Davidson and Hogan, metthe Section 13D Group to discuss the proposed transaction.

Also on May 17, 2021, a special meeting of the AB Board was convened to consider the proposed definitivemerger transaction. Members of executive management and representatives of KBW and Jones Day attended the meeting at the invitation of the AB Board. The AB Board was provided with a set of meeting materials in advance of the meeting, including substantially final drafts of the merger agreement, as negotiated to date. Representatives of Davidson reviewed the financial aspectsvoting agreements which included key members of the proposed merger. Hogan reviewedSection 13D Group and the specificDavis Group, the non-competition/non-solicitation agreements, and a summary of the material terms of the merger agreement prepared by Jones Day. Jones Day discussed with the directors their fiduciary duties under applicable law and reviewed the process involvedaccompanying legal standards. Jones Day proceeded to review in negotiating its terms. The SBCdetail with the AB Board considered all these matters and determined to continue with negotiations of the proposed merger.

On September 30, 2019, the SBC Board, together with representatives of Davidson and Hogan, again met to consider the negotiated proposed definitive merger agreement. Hogan reviewed the terms of the proposed merger agreement, andincluding the changes to the proposed merger agreement since the SBC Board’s September 19, 2019, meeting, and all relatedterms of various ancillary agreements. Representatives of Davidsondocuments. KBW then reviewed the financial aspects of the proposed mergertransaction, including the financial analyses with respect to the proposed transaction that KBW performed, and KBW rendered to SBC a verbal fairnessthe AB Board an opinion, which was subsequentlyinitially rendered verbally and confirmed in writing,a written opinion dated May 17, 2021, to the effect

that, as of thatsuch date and subject to the procedures followed, assumptions made, matters considered, and qualifications and limitations on the review undertaken by Davidson,KBW as set forth in its opinion, the merger considerationexchange ratio in the proposed merger with Glacier was fair, from a financial point of view, to the holders of SBCAB common stock. Among other mattersshares. The AB Board considered the SBC Board reviewedvalues of the specificother acquisition proposals that had been previously received, taking into account changes in stock prices, and noted that the consideration in the proposed transaction with Glacier was still clearly the best for shareholders.

After considering the proposed terms of the merger agreement the form and value of the consideration to be received by SBC shareholders, the price and historical performance of Glacier common stock and related dividend payouts, current market conditions including comparable bank merger and acquisition transactions, the employment of certain SBC employees following the merger, and the implications of the merger to SBC’s employees, customers, and communities. After due consideration of these and other matters,transaction documents, and taking into consideration the fairness opinionmatters discussed during that meeting and prior meetings of Davidson, the SBCAB Board, unanimously approved entering intoincluding the merger agreement.

The parties entered intostrategic options discussed at those meetings and the merger agreement on September 30, 2019. Afterfactors described under the closesection of business on September 30, 2019,this proxy statement/prospectus entitled “Recommendation of the parties issued a joint press release announcing the merger.

AB Board and Reasons for the Merger, – SBC

At a board meeting held on September 30, 2019,” the SBCAB Board determined that the terms of the merger agreement werewas fair to and in the best interests of SBCAB and itsAB shareholders, and recommended that SBC’s shareholders vote for approvalthe AB Board unanimously approved, adopted and declared advisable the execution, delivery and performance of the merger agreement. Inagreement and the course of reaching this determination and related decision to approvetransactions contemplated by it, including the merger, agreement, the SBC Board evaluatedand recommended to AB’s shareholders that they approve the merger and the merger agreement in consultationagreement.

AB executive management then discussed with the AB Board the proposed communication plan, including the public announcement, internal meeting with employees, and schedule for media and investor calls.

On May 18, 2021, a special meeting of the Glacier Board was convened to consider the proposed merger transaction. Members of executive and senior management and representatives of SBCD.A. Davidson and SBC’s financial advisorMiller Nash also attended the meeting at the invitation of the Glacier Board. The Glacier Board was provided with a set of meeting materials in advance of the meeting, including substantially final drafts of the merger agreement, the voting agreements, the non-competition/non-solicitation agreements, and a comprehensive due diligence review summary. Miller Nash discussed with the directors their fiduciary duties under applicable law and reviewed the accompanying legal standards. Members of Glacier’s executive and senior management team then reviewed the enhanced due diligence process in detail. This included a review of the credit, compliance and legal counsel. In reaching its determination,findings. D.A. Davidson then reviewed the SBCfinancial aspects of the proposed transaction, including the financial analyses with respect to the proposed transaction that D.A. Davidson performed. Miller Nash proceeded to review in detail with the Glacier Board considered a numberthe terms of factors. Such factors also constituted the reasons thatmerger agreement, including the SBC Board determined to approveterms of various ancillary documents. After considering the proposed terms of the merger agreement and to recommendrelated transaction documents, and taking into consideration the matters discussed during that SBCmeeting and prior meetings of the Glacier Board, the Glacier Board determined that the merger was in the best interests of Glacier and Glacier shareholders, vote in favorand the Glacier Board unanimously approved, adopted and declared advisable the execution, delivery and performance of the merger agreement. The following discussionagreement and the transactions contemplated by it, including the merger.

Following receipt of approval of the informationmerger agreement and factors considered bytransaction from the SBCGlacier Board on May 18, 2021, AB and Glacier executed the merger agreement, each of the directors and each of the executive officers of AB, the Davis Group and members of the Section 13D Group executed the voting agreements with Glacier, each of the directors of AB executed the non-solicitation/non-competition agreements with Glacier, and certain executive officers of AB executed their employment agreements with Glacier. On the afternoon of May 18, 2021, each of Glacier and AB issued press releases announcing the execution of the merger agreement.

On May 19, 2021, Glacier and AB each made a customary filing with the SEC on Form 8-K regarding the execution of the merger agreement and included a copy of the merger agreement as an exhibit to such filing.

Recommendation of the AB Board and Reasons for the Merger

After careful consideration, at a meeting held on May 17, 2021, the AB Board determined that the merger agreement, including the merger of the Bank into Glacier Bank, is not intended to be exhaustive; it does, however, include all material factors considered byin the SBC Board.best interests of AB and AB’s shareholders and approved and adopted the merger agreement.

In reaching its decision to approve the merger agreement, the SBCmerger and the other transactions contemplated by the merger agreement and to recommend that the AB shareholders vote “FOR” the proposal to approve the merger agreement, the AB Board evaluated the merger agreement, the merger, and the other transactions contemplated by the merger agreement in consultation with AB’s executive management, as well as AB’s financial advisor, KBW, and legal advisor, Jones Day, and considered various factors, including, without limitation, the following:following material factors:

The foregoing discussion of the information and factors considered by the AB Board is not intended to be exhaustive, but, rather, includes the material factors considered by the AB Board. In reaching its decision to approve the merger agreement, the merger of the Bank into Glacier Bank and the other transactions contemplated by the merger agreement, the AB Board did not quantify or assign any relative weights to the factors considered, and individual directors may have given different weights to different factors. The AB Board considered all these factors as a whole and overall considered the factors to be favorable to, and support, its determination to approve the merger agreement.

It should be noted that this explanation of the AB Board’s reasoning and all other information presented in this section is forward-looking in nature and, therefore, should be read in light of the factors discussed under the heading “Cautionary Statement Regarding Forward-Looking Statements.”

Opinion of SBC’sAB’s Financial Advisor

On May 2, 2019, SBC entered into an engagement agreement with D.A. Davidson & Co.AB engaged KBW to render financial advisory and investment banking services to SBC. As part of its engagement, Davidson agreedAB, including an opinion to assist SBC in analyzing, structuring, negotiating and, if appropriate, effecting a transaction between SBC and another corporation or business entity. Davidson also agreed to provide the SBCAB Board with an opinion as to the fairness, from a financial point of view, to the common shareholders of AB of the merger considerationexchange ratio (referred to be paid toelsewhere in this proxy statement/prospectus as the holders of SBC commonper share stock consideration) in the proposed merger. SBC engaged DavidsonAB selected KBW because DavidsonKBW is a nationally recognized investment banking firm with substantial experience in transactions similar to the merger and is familiar with SBC and its business.merger. As part of its investment banking business, DavidsonKBW is continually engaged in the valuation of financial institutionsservices businesses and their securities in connection with mergers and acquisitions and other corporate transactions.acquisitions.

On September 30, 2019,As part of its engagement, representatives of KBW attended the SBCmeeting of the AB Board held a meeting to evaluateon May 17, 2021, at which the AB Board evaluated the proposed merger.transaction. At this meeting, DavidsonKBW reviewed the financial aspects of the proposed merger and rendered to the AB Board an opinion to the SBC Boardeffect that, as of such date and based upon and subject to the procedures followed, assumptions made, procedures followed, matters considered, and qualifications and limitations on the review undertaken by KBW as set forth in its opinion, the merger consideration to be paid toexchange ratio in the holders of SBC common stockproposed merger was fair, from a financial point of view, to suchthe holders of SBCAB common stock inshares. The AB Board directors approved the proposed merger.merger agreement at this meeting.

The full text of Davidson’s written opinion, dated September 30, 2019, is attached as Appendix C to this proxy statement-prospectus and is incorporated herein by reference. The description of the opinion set forth herein is qualified in its entirety by reference to the full text of such opinion. SBC’s shareholders are urged to read the opinion, which is attached as Appendix B to this document and is incorporated herein by reference, and describes the procedures followed, assumptions made, matters considered, and qualifications and limitations on the review undertaken by KBW in its entirety.preparing the opinion.

Davidson’sKBW’s opinion speaks only as of the date of the opinion and Davidson undertakes no obligation to revise or update its opinion. The opinion iswas for the information of, and was directed to, the SBCAB Board and addresses(in its capacity as such) in connection with its consideration of the financial terms of the merger. The opinion addressed only the fairness, from a financial point of view, of the exchange ratio in the merger consideration to be paid to the holders of SBCAB common stock in the proposed merger. The opinion doesshares. It did not address and Davidson expresses no view or opinion with respect to, (i) the underlying business decision of SBCAB to engage in the merger (ii) the relative merits or effect ofenter into the merger as comparedagreement or constitute a recommendation to the AB Board in connection with the merger, and it does not constitute a recommendation to any alternative business transactionsholder of AB common shares or strategies that may be or may have been available to or contemplated by SBC or the SBC Board, or (iii) any legal, regulatory, accounting, tax or similar matters relating to SBC, its shareholders or relating to or arising outshareholder of the merger. The opinion expresses no view or opinionany other entity as to any terms or other aspects ofhow to vote in connection with the merger except for the merger consideration. SBC and Glacier determined the merger consideration through the negotiation process. The opinion does not express any view as to the amount or nature of the compensation to any of SBC’s or Glacier’s officers, directors or employees, or any class ofother matter, nor does it constitute a recommendation regarding whether or not any such persons, relative to the merger consideration,shareholder should enter into a voting, shareholders’ or affiliates’ agreement with respect to the fairness ofmerger or exercise any dissenters’ or appraisal rights that may be available to such compensation. Theshareholder.

KBW’s opinion has beenwas reviewed and approved by Davidson’sKBW’s Fairness Opinion Committee in conformity with its policies and procedures established under the requirements of Rule 5150 of the Financial Industry Regulatory Authority.

In connection with rendering itsthe opinion, DavidsonKBW reviewed, analyzed and relied upon material bearing upon the financial and operating condition of AB and Glacier and bearing upon the merger, including, among other things, the following:things:

as KBW deemed relevant to its inquiry. In addition, KBW considered the results of operationsthe efforts undertaken by AB, with KBW’s assistance, to solicit indications of interest from third parties regarding a potential transaction with AB.