As filed with the Securities and Exchange Commission on July 2, 2021September 14, 2023

Registration No. 333-            

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-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, a non-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 Rule 12b-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:

CALCULATION OF REGISTRATION FEE

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 JULY 2, 2021SEPTEMBER 14, 2023

MERGER PROPOSED – YOUR VOTE IS VERY IMPORTANT

Dear AltabancorpCommunity Financial Group, Inc. Shareholders:

As you may know, the boards of directors of AltabancorpCommunity Financial Group, Inc. (“AB”CFGW”) and Glacier Bancorp, Inc. (“Glacier”) have each unanimously approved a merger of ABCFGW with and into Glacier, subject to approval by ABCFGW shareholders and appropriate bank regulators. Immediately following the merger, AB’sCFGW’s subsidiary AltabankWheatland Bank (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 May 18, 2021August 8, 2023 (the “merger agreement”), each outstanding ABCFGW common share as of the effective time (including each share issued upon settlement of each unvested restricted stock unit) will be exchanged for 0.79711.0931 shares of Glacier common stock (the “per share stock consideration”), subject to certain adjustments, with cash paid in lieu of fractional shares. The common stock of Glacier trades on The Nasdaq Global Select MarketNew York Stock Exchange under the symbol “GBCI.” TheCFGW’s common stock of AB tradesis currently quoted on The Nasdaq Capital Marketthe OTC Markets under the symbol “ALTA.“CFGW.”

The per share stock consideration is subject to adjustment in the event that the average closing price for Glacier common stock over a 20-day period prior to closing is more than $74.15 or less than $49.43. In such event either Glacier or AB, respectively, may provide notice to terminate the merger agreement, but the merger agreement will not be terminated if either AB 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.

The per share stock consideration is subject to further adjustment if AB’sCFGW’s closing capital, after being adjusted in accordance with the terms of the merger agreement, is less than the minimum required, which is $342,937,000$49,200,000 (subject to specified adjustments). In any such event, the per share stock consideration will be reduced on a per share basis in accordance with the formula set forth in the merger agreement. See “The Merger – Merger Consideration.”

If AB’sCFGW’s closing capital, after being adjusted in accordance with the terms of the merger agreement, is in excess of $49,200,000, CFGW may, prior to the minimum required, AB mayclosing of the merger, pay a special cash dividend to its shareholders in the amount of such excess. See “The Merger – Merger Consideration.”

Assuming for purposes of illustration only that the average closing price for Glacier common stock is $[___],    ], which was the closing price of Glacier common stock on [___], 2021,September [    ], 2023, as quoted on The Nasdaq Global Select Market,New York Stock Exchange, for each of your ABCFGW common shares, you will receive consideration with an estimated current value of $[___],    ], consisting of 0.79711.0931 shares of Glacier common stock.

Assuming the exchange ofthat all outstanding ABCFGW common shares are exchanged for stock in accordance with the merger agreement and the per share stock consideration is not adjusted as described above, ABCFGW shareholders will, in the aggregate, receive approximately [___]2,429,950 shares of Glacier common stock in the merger, representing approximately [___]%2.14% of Glacier’s outstanding common stock after taking into account Glacier shares to be issued in the merger.

ABCFGW will hold a special shareholders’ meeting to vote on the merger agreement on [___], 2021,[    ], 2023, at [___] Mountain Time. This special meeting will be held in virtual format only.[    ] Pacific Time at 222 North Wall Street, Lower Level Conference Room, Spokane, Washington 99201. 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 participate 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 1413 for risk factors relating to the merger whichthat you should consider.

The board of directors of ABCFGW 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

Len E. Williams

President and Chief Executive Officer, Altabancorp

/s/ Richard T. Beard

Richard T. Beard

Board Chair, Altabancorp

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 ABCFGW and are subject to investment risk, including the possible loss of principal.

This proxy statement/prospectus is dated [___], 2021,[    ], 2023, and is first being mailed to

AB CFGW shareholders on or about [___], 2021.[    ], 2023.

1 East Main222 North Wall Street, American Fork, Utah 84003Suite 300, Spokane, Washington 99201

NOTICE OF SPECIAL MEETING OF SHAREHOLDERS OF

ALTABANCORP^TMCOMMUNITY FINANCIAL GROUP, INC.

TO BE HELD ON [    ], 20212023

To the Shareholders of Altabancorp:Community Financial Group, Inc.:

A special meeting of the shareholders of AltabancorpCommunity Financial Group, Inc. (“AB”CFGW”) will be held on [___], 2021.[        ], 2023 at [        ] Pacific Time, at 222 North Wall Street, Lower Level Conference Room, Spokane, Washington 99201. 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 ABCFGW common shares at the close of business on [___], 2021,[        ], 2023, 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 AB’sCFGW’s common stock entitled to vote is required for approval of the merger agreement. To that end, AB’sCFGW’s directors and certain of CFGW’s executive officers and certain significant shareholders have signed agreements to vote their shares in favor of the merger agreement. As of the record date, to CFGW’s knowledge, such persons were entitled to vote [_________][612,869] shares representing approximately [____][28.7]% of all outstanding ABCFGW common shares. As of the record date, there were [__________] AB[2,136,808] CFGW common shares outstanding.

REFERENCES TO ADDITIONAL INFORMATION

Both Glacier Bancorp, Inc. (“Glacier”), and Altabancorp (“AB”), file annual, quarterly and special reports, proxy statements and other business and financial information with the Securities and Exchange Commission (the “SEC”) electronically. The SEC maintains a website located at http://www.sec.gov containing this information. You can also obtain, free of charge, documents that Glacier files with the SEC at www.glacierbancorp.com under the tab “SEC Filings” or documents that AB files with the SEC at www.altabancorp.com in the “Investor Relations” section, under the heading “SEC Filings.” The information

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

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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 AltabancorpCommunity Financial Group, Inc. (“AB”CFGW”) common stock with respect to its proposed merger with Glacier Bancorp, Inc. (“Glacier”). The merger cannot be completed unless ABCFGW receives the affirmative vote of the holders of at least a majority of the outstanding shares of AB’sCFGW’s common stock entitled to vote on the matter. ABCFGW 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 “AB“CFGW Special ShareholdersShareholders’ Meeting.”

This document is both a proxy statement of ABCFGW and a prospectus of Glacier. It is a proxy statement because the officers and board of directors of ABCFGW (the “AB“CFGW Board”) are soliciting proxies from AB’sCFGW’s shareholders in connection with voting on the merger. It is a prospectus because Glacier will issue, and you will acquire in exchange for your CFGW common stock, shares of itsGlacier’s common stock in exchange for ABCFGW common shares as the consideration to be paid in the merger.

What will happen in the merger?

In the proposed merger, ABCFGW will merge with and into Glacier, with Glacier surviving the merger. Immediately following the merger, AltabankWheatland Bank (the “Bank”) will be merged into Glacier’s subsidiary Glacier Bank. Shares of Glacier will continue to trade on The Nasdaq Global Select Market,New York Stock Exchange, with the trading symbol “GBCI.”

What will ABCFGW shareholders receive in the merger?

Under the terms of the merger agreement, each ABCFGW common share (including each share to be issued upon settlement of each unvested restricted stock unit (“RSU”)) will be exchanged for 0.79711.0931 shares of Glacier common stock (the “per share stock consideration”), subject to 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 of Glacier common stock on [___], 2021)[            ], 2023), each ABCFGW common share would be exchanged for 0.79711.0931 shares of Glacier common stock with a total value equal to $[___].            ].

The per share stock consideration 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.

In addition, the per share stock consideration will be subject to reduction if the “AB“CFGW Closing Capital,” as defined and determined in accordance with the merger agreement, is less than the target of $342,937,000,$49,200,000, subject to certain adjustments. In such event, the number of shares of Glacier common stock to be issued will be reduced on a per-share basis in accordance with the formula set forth in the merger agreement. See “The Merger – Merger Consideration.”

If the ABCFGW Closing Capital exceeds $342,937,000,$49,200,000, subject to certain adjustments, ABCFGW may, upon written notice to Glacier and effective 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, AB shareholders will give the AB Board the authority to elect to cause AB to accept a reduction on a per-share basis of the number of shares of Glacier common stock to be issued in the merger if the Glacier average closing price exceeds $74.15, as described below. See “The Merger – Termination of the Merger Agreement.”

Assuming the exchange ofthat all outstanding ABCFGW common shares are exchanged for Glacier common stock as per share stock consideration in accordance with the merger agreement and the per share stock consideration is not adjusted as

Incentive Stock Option Plan the Altabancorp 2020 Equityof 2018, Non-Qualified Stock Option Plan of 2018, Incentive Stock Option Plan of 2005, and the People’s Utah Bancorp Amended and Restated 2008Non-Qualified Stock IncentiveOption Plan of 2005 (the “AB“CFGW 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 ABCFGW Options will be paid in cash an amount per share equal to the spread, if any, between (a) the product of the average of the closing sales prices of one share of Glacier common stock on The New York Stock Exchange for the 20 trading days ending on the tenth business day immediately preceding the effective date of the merger (the “Glacier average closing price (as defined in the merger agreement)price”) multiplied by the per share stock consideration and (b) the exercise price per share of such ABCFGW Option, net of any cash which must be withheld under applicable tax laws. Any ABCFGW Option that has an exercise price per share that is equal to or greater than the total consideration value per shareamount described in (a) above 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 Glacier average of the closing sales prices of one share of Glacier common stock on The Nasdaq Global Select Market for the 20 trading days ending on the tenth business day immediately preceding the effective date of the merger.price.

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 ABCFGW 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 during the fourth quarter of 2021.2023. 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 AB.CFGW. 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 ABCFGW common shares entitled to vote on the matter at the ABCFGW special meeting, after the merger has received all required 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 eventmerger will be completed effective as of the closing haslast day of the month occurring at least five business days after the fulfillment or waiver of each condition to the merger and receipt of all required approvals; provided that Glacier will not occurred by November 30, 2021,be required to consummate the first datemerger on which the closing may occur isDecember 31, 2023 or on January 31, 2022.2024.

Who may vote at the special meeting?

The ABCFGW Board has set [___], 2021[            ], 2023 as the record date for the special meeting. If you were the owner of ABCFGW common shares at the close of business on [___], 2021,[            ], 2023, you may vote at the special meeting. Each holder of ABCFGW common shares is entitled to one vote for each ABCFGW common share owned as of the record date.

What constitutes a quorum for the special meeting?

The quorum requirement for the special meeting is the presence at the meetingin person or by proxy of a majority of the total number of outstanding ABCFGW common shares entitled to vote.

What vote is required to approve the merger agreement?

Approval of the merger agreement requires the affirmative vote of the holders of at least a majority of the outstanding shares of AB’sCFGW’s common stock entitled to vote on the matter. As described in this proxy statement/prospectus, AB’sCFGW’s directors and certain of CFGW’s executive officers and certain significant shareholders have agreed to vote the shares they are entitled to vote in favor of the merger agreement. As of the record date, to CFGW’s knowledge, such persons were entitled to vote [_________] AB[612,869] CFGW common shares, representing approximately [___][28.7]% of all outstanding ABCFGW common shares. See “AB“CFGW Special Shareholders’ Meeting” and “The Merger – Voting Agreements.”

What vote is required to approve the merger-related named executive compensation proposal?

The proposal to approve merger-related named executive compensation will be approved if the votes cast in favor of the proposal exceed the votes cast opposing the proposal, assuming a quorum is present.

What vote is required to approve the adjournment of the special meeting, if necessary or appropriate?

The proposal to adjourn the special meeting, if necessary or appropriate, including adjournments to solicit additional proxies, will be approved if the votes cast in favor of the proposal exceed the votes cast opposing the proposal, whether or not a quorum is present. Each of the Voting Agreements entered into by AB’sproposal. CFGW’s directors and executive officers and certain significant shareholders provides that such persons have also agreed to vote thetheir shares subject to such agreement in favor of any proposal to adjourn the special meeting if there are not sufficient votes to approve the merger agreement. See “The Merger – Voting Agreements.”

Can I vote in person?

Yes. Although the CFGW Board requests that you submit a proxy through the Internet, by telephone or by returning the proxy card accompanying this proxy statement/prospectus, all shareholders are invited to attend the shareholders’ meeting. Shareholders of record on [                            ], 2023 can vote in person at the special meeting.

How do I vote?

If you were a shareholder of record on [___], 2021,[            ], 2023, you may vote on the proposals presented at the special meeting at the meetingin person or by proxy. We urge you to vote promptly by submitting a proxy to vote through the Internet, by telephone, or by completing the enclosed proxy card. Even if you plan to attend the special meeting, we recommend that you vote your shares in advance as described below so that your vote will be counted if you later decide not to attend the virtual special meeting.

What if I fail to submit a proxy or to instruct my broker, bank or other nominee?

If you fail to properly submit a proxy or to instruct your broker, bank or other nominee to vote your ABCFGW common shares, and you do not attend the special meeting and vote your shares in person, your shares will not be voted. This will have the same effect as a vote “AGAINST” approval of the merger agreement, but will have no impact on the outcome of the other proposals.

Can I attend the special meeting and vote my shares at the meeting?

Yes. Although the AB Board requests that you submit a proxy through the Internet, by telephone or by returning the proxy card accompanying this proxy statement/prospectus, all shareholders are invited to attend the shareholder meeting. Shareholders of record on [__________], 2021 can vote at the special meeting by following the instructions available on the meeting website.

Can I change my vote after I have submitted my proxy?

Yes. If you do not hold your shares in “street name,” there are three ways you may change your vote at any time after you have submitted your proxy and before your proxy is voted at the special meeting:

If you submit a written notice of revocation, it must be received by AB’sCFGW’s Secretary prior to the vote at the special meeting. If you grant a new proxy by telephone or Internet, your revised instructions must be received by 11:59 p.m., MountainPacific Time, one day before the meeting date.

If you have instructed a bank, broker or other nominee to vote your shares, you must follow the directions you receive from your bank, broker or other nominee to change your voting instructions.

What happens if I return my proxy but do not indicate how to vote my shares?

If you sign and return your proxy card but do not provide instructions on how to vote your ABCFGW common shares at the special meeting of shareholders, your ABCFGW common shares will be voted “FOR” the proposal to approve the merger agreement “FOR” the merger-related named executive compensation proposal and “FOR” approval of one or more adjournments of the special meeting.

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 returnreturning it in the enclosed envelope as soon as possible so that your ABCFGW common shares can be voted at AB’sCFGW’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. No. Please do not send your ABCFGW common share certificates with your proxy card.card. You will receive written instructions from Glacier’s exchange agent promptly following the closing of the merger on how to exchange your ABCFGW common share certificates for the merger consideration. In the meantime, you may wish to begin collecting any certificates in your possession.

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 ABCFGW Board in approving the merger agreement. See “Background of and Reasons for the Merger.”

Do I have appraisal or dissenters’ rights?

No. Under UtahYes. If you are a CFGW shareholder and you do not agree with the merger, do not vote in favor of the merger agreement, and take certain other actions required by Washington law, AB shareholders are not entitledyou will have dissenters’ rights under Sections 23B.13.010 through 23B.13.310 of the Revised Code of Washington. Exercise of these rights will result in the purchase of your shares of CFGW common stock at “fair value,” as determined in accordance with Washington law. If you elect to exercise appraisal rights in connectionthis right, we encourage you to consult with the merger.your financial and legal advisors. 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 shareholdersshareholders’ meeting, or your proxy, or if you need additional copies of this document or a proxy card, you should contact:

AltabancorpCommunity Financial Group, Inc.

1 East Main222 North Wall Street

American Fork, Utah 84003Suite 300

Spokane, Washington 99201

Attention: CorporateTina Campbell, Board Secretary

Telephone: (801)(509) 642-3998242-5626

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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 ABCFGW 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 ABCFGW 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 AB.CFGW. 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 AB common share 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 $74.15 and Glacier elects to terminate the merger agreement, the AB Board could determine, without resoliciting the vote of AB shareholders, whether or not to accept a decrease on a per-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.CFGW.

The businesses of Glacier and ABCFGW 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 ABCFGW 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 ABCFGW and certain factors to be considered in connection with AB’sCFGW’s business, see “Information Concerning Altabancorp”Community Financial Group, Inc.” and the documents incorporated by reference in this document and referred to under “Where You Can Find More Information.”

The merger agreement limits AB’sCFGW’s ability to pursue other transactions and provides for the payment of a break-up fee if ABCFGW does so.

While the merger agreement is in effect, subject to very narrow exceptions, ABCFGW and its directors, officers, employees, agents and representatives are prohibited from initiating or encouraging inquiries with respect to alternative acquisition proposals. The prohibition limits AB’sCFGW’s ability to seek offers from other potential acquirersacquirors that may be superior from a financial point of view to the proposed transaction. If ABCFGW 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, ABCFGW will be required to pay a $35,000,000$3,100,000 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.”

benefits of the merger. As with any merger of banking institutions, there also may be disruptions that cause the Bank to lose customers or cause customers to take their deposits out of the Bank.

UnanticipatedWe may face unanticipated costs relating to the merger could reduce Glacier’s future earnings per share.merger.

Glacier believes that it has reasonably and conservatively estimated the likely costs of integrating the operations of the Bank into Glacier Bank, and the incremental costs of operating as a combined financial institution. However, it is possible that unexpected transaction costs or future operating expenses, as well as other types of unanticipated adverse developments,costs, including as a result of the substantial commitment of time and resources by Glacier’s management to the merger, could have a material adversenegative effect on the results of operations and financial condition of Glacier after the merger. If the merger is completed and unexpected costs are incurred, the merger could have a dilutive effect on Glacier’s earnings per share, meaning earnings per share could be less than they would be if the merger had not been completed.

The merger agreement may be terminated in accordance with its terms and the merger may not be completed, which could have a negative impact on AB.CFGW.

The merger agreement with Glacier is subject to a number of conditions that must be fulfilled in order to close. Those conditions include: approval by the shareholders of AB,CFGW, receipt of all required regulatory approval,approvals, the continued accuracy of certain representations and warranties by both parties (subject to the materiality standards set forth in the merger agreement), and the performance by both parties of certain covenants and agreements. In addition, certain circumstances exist in which ABCFGW may terminate the merger, including by accepting a superior proposal or by electing to terminate if Glacier’s stock price declines below a specified level.proposal. There can be no assurance that the conditions to closing the merger will be fulfilled or that the merger will be completed.

If the merger agreement is terminated, there may be various consequences to AB,CFGW, including:

If the merger agreement is terminated and the AB Board approves another merger or business combination, under certain circumstances AB may be required to pay Glacier a $35,000,000 termination fee. AB’s shareholders cannot be certain that AB will be able to find a party willing to pay an equivalent or more attractive price than the price Glacier has agreed to pay in the merger.

The opinion of AB’sCFGW’s financial advisor delivered to the ABCFGW Board before the execution of the merger agreement does not reflect any changes in circumstances subsequent to the date of the opinion.

The opinion of KBWPiper Sandler regarding the fairness, from a financial point of view, of the exchange ratioper share stock consideration in the merger was delivered to the ABCFGW Board on May 17, 2021,August 8, 2023, and speaks only as of such date. Changes in operations and prospects of Glacier and AB,CFGW, general market and economic conditions, and other factors both within and outside of Glacier’s and AB’sCFGW’s control may significantly alter the relative value of the companies by the time the merger is completed. KBW’sPiper Sandler’s opinion does not speak as of the time the merger will be completed or as of any date other than the date of such opinion.

CFGW 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 AB.CFGW. Based on the anticipated number of Glacier common shares to be issued in the merger, it is anticipated that the ABCFGW shareholders will only own approximately 13.7%2.14% of all of the outstanding shares of Glacier’s common stock following the merger. Because of this, AB’sCFGW’s shareholders will have significantly less influence on the management and policies of Glacier than they now have on the management and policies of 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 AB shareholders, which would further reduce their ownership percentage in, and voting control over, Glacier.CFGW.

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

Glacier and ABCFGW intend the merger to qualify as a reorganization within the meaning of Section 368(a) of the Internal Revenue Code. Glacier and AB,CFGW, 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 either from taking a contrary position. Neither Glacier nor ABCFGW 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. Furthermore, if the merger fails to qualify as a reorganization, Glacier, as successor to AB,CFGW, may incur a significant tax liability since the merger would be treated as a taxable sale of AB’sCFGW’s assets for U.S. federal income tax purposes.

Glacier and ABCFGW 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.CFGW. These uncertainties may impair Glacier’s and AB���sCFGW’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 ABCFGW to seek to change existing business relationships with Glacier, ABCFGW or the combined company or fail to extend an existing relationship with Glacier, ABCFGW or the combined company.

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

In addition, if the merger is not completed, Glacier and/or ABCFGW may experience negative reactions from the financial markets and from their respective customers and employees. Glacier and/or ABCFGW also could be subject to litigation related to any failure to complete the merger or to enforcement proceedings commenced against Glacier or ABcause them to perform their respective obligations under the merger agreement. If the merger is not completed, Glacier and ABCFGW cannot assure their respective shareholders that the risks described above will not materialize and will not materiallynegatively affect the business, financial results andor stock prices of Glacier and/or AB.CFGW.

The merger is subject to the receipt of approvals and/or waivers or non-objections from governmental authorities that may delay the date of completion of the merger or impose conditions that could have an adverse effect on Glacier.

Before the merger may be completed, various approvals, waivers or non-objections must be obtained from state and federal governmental authorities, including the Federal Deposit Insurance Corporation, the Board of Governors of the Federal Reserve System, the Commissioner of the Montana Division of Banking and Financial Institutions, and the UtahWashington State Department of Financial Institutions. SatisfyingObtaining the approval or satisfying the requirements of these governmental authorities may delay the date of completion of the merger.merger, including due to any or all of the following: an adverse development in either party’s regulatory standing or any other factors considered by regulators in granting such approval; governmental, political or community group inquiries, investigations or opposition; or changes in legislation or the political environment. In addition, these governmental authorities may includeimpose conditions on the completion of the merger, or require changes to the terms of the merger. While Glacier and ABCFGW do not currently expect that any such conditions or changes would result in a material adverse effect on Glacier, there can be no assurance that they will not, and such conditions or changes could have the effect of delaying completion of the merger, or imposing additional costs on or limiting the revenues of Glacier following the merger, any of which might have a material adverse effect on Glacier following the merger. The parties are not obligated to complete the merger should any required regulatory approval, waiver or non-objection contain a condition or requirement not normally imposed in such transactions that would deprive Glacier of the economic or business benefits of the merger in a manner that is material relative to the aggregate economic or business benefits of the merger to Glacier, subject to certain rights grantedGlacier.

Certain CFGW directors and executive officers may have interests in the merger agreementthat differ from, or are in addition to, appeal any denialthe interests of suchthe shareholders.

In addition to their interests as shareholders generally, certain members of the CFGW Board and executive management may have other interests in the merger. The CFGW Board was aware of these interests and considered them, among other things, when deciding to approve the merger agreement. For a more detailed discussion of these interests, see “Interests of CFGW Directors and Executive Officers in the Merger.”

Recent events impacting the financial services industry could exacerbate the risks associated with the merger.

The adverse events during the first part of 2023 involving Silicon Valley Bank, Signature Bank, and First Republic Bank caused significant volatility in the trading prices of stock of publicly traded bank holding companies and have decreased confidence in banks among depositors and investors. These adverse events also led bank regulators to signal further review of regulatory approval.requirements and the potential for changes to laws or regulations governing banks and bank holding companies. These ramifications could extend to the merger and increase the risk of losing depositors and heightened regulatory scrutiny of the merger.

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Risks Associated with AB’sGlacier’s Business

ABGlacier is, and will continue to be, subject to the risks described in AB’sGlacier’s Annual Report on Form 10-K for the fiscal year ended December 31, 2020,2022, as updated by its Quarterly Report on Form 10-Q for the quarter ended March 31, 2021,June 30, 2023, and subsequent Current Reports on Form 8-K, and Quarterly Reports on Form 10-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: (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 Glacier’s and AB’sCFGW’s plans, objectives, expectations, intentions, projected financial information, future opportunities and any other statements regarding Glacier’s and AB’sCFGW’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 (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’sCFGW’s management and are inherently subject to significant business, economic and competitive uncertainties and contingencies, many of which are beyond Glacier’s and AB’sCFGW’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:

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The foregoing list of factors is not intended to be exhaustive. These forward-looking statements reflect Glacier’s and AB’sCFGW’s current views with respect to future events and are based on numerous assumptions and assessments made by Glacier and ABCFGW 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’sCFGW’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 ABCFGW or any person acting on behalf of Glacier or ABCFGW are expressly qualified in their entirety by the cautionary statements above. Neither Glacier nor ABCFGW 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.

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COMPARATIVE STOCK PRICE AND DIVIDEND INFORMATION

Glacier Common Stock

Glacier common stock is quoted on The New York Stock Exchange under the symbol “GBCI.” The following table sets forth for the closing saleperiods indicated:

forth for the periods indicated, the high and low quotations for CFGW common stock along with the aggregate number of shares publicly reported as traded for each applicable quarter.

ABCFGW SPECIAL SHAREHOLDERS’ MEETING

Date, Time, Place

The ABCFGW special meeting of shareholders will be held on [___], 2021,[            ], 2023, at [___] Mountain Time. The special meeting will be held in virtual meeting format only. In order to attend the special meeting, AB shareholders must register[            ] Pacific Time at www.proxydocs.com/ALTA by 5:00 p.m. Mountain Time on [__], 2021.222 North Wall Street, Lower Level Conference Room, Spokane, Washington 99201.

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 AB’sCFGW’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 the votes cast in favor of the proposal exceed the votes cast opposing the proposal, whether or not a quorum is present.proposal.

Purpose

At the special meeting, ABCFGW shareholders will:

Record Date; Shares Outstanding and Entitled to Vote

The ABCFGW Board has fixed the close of business on [___], 2021,[            ], 2023, as the record date for determining the holders of ABCFGW common shares 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[2,136,808] CFGW common shares issued and outstanding. Holders of record of ABCFGW common shares on the record date are entitled to one vote per share. Unvested RSUs do not have voting rights.

AB’sCFGW’s directors and certain of CFGW’s executive officers and certain significant shareholders have agreed to vote all ABCFGW common shares 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, to CFGW’s knowledge, a total of [_________] AB[612,869] CFGW common shares, representing approximately [____][28.7]% of all outstanding ABCFGW common shares, are subject to voting agreements. See “The Merger – Voting Agreements”.

Votes Required and Quorum

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

For voting purposes, however, shares must be affirmatively voted FOR approval of the merger agreement in order to be counted as votes in favor of the merger. As a result, abstentions and broker non-votes with respect to the proposal to approve the merger agreement will have the same effect as votes against such proposal.

Voting, Solicitation, and Revocation of Proxies

If you are a holder of record of ABCFGW common shares 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 proxy FOR the approval of the merger agreement, FOR the proposal to approve merger-related compensation of AB’s named executive officers and FOR 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:

ABCFGW is soliciting the proxy for the special meeting on behalf of the ABCFGW Board. ABCFGW will bear the cost of solicitation of proxies from its shareholders. In addition to using the mail, ABCFGW may solicit proxies in person or by personal interview, telephone, and facsimile.email or facsimile, in each case without compensation. 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. ABCFGW 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 held directly in your name as the shareholder of record may be voted duringin person at the special meeting by followingmeeting. If you choose to vote your CFGW common shares in person, please bring the instructions available on the meeting website.enclosed proxy card or proof of identification. Even if you plan to participate atattend the virtual special

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 ABCFGW 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 ABCFGW and the ABCFGW 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’sCFGW’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 meetingin person 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 ABCFGW common shares is a condition to the completion of the merger.

The ABCFGW Board recommends that ABCFGW 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,

BACKGROUND OF AND REASONS FOR THE MERGER

Background of the Merger

As part of its ongoing strategic planning to enhance shareholder value, the CFGW Board and executive management regularly review and assess CFGW’s strengths, weaknesses, strategic opportunities and challenges, in an ever changing and more complex operating environment. The ABCFGW Board considered the prospects for continued strong growth and profitability, particularly in light of the difficulties operating as an independent community bank under current economic, regulatory and competitive conditions. Like many other banks, CFGW experienced increasing costs related to information technology, regulatory compliance, product development and personnel, to remain competitive with bank and non-bank competitors, including financial technology companies. In addition, after over 40 years of operations, CFGW was facing a heightened level of succession risk that was difficult to address, as an increasing number of CFGW’s directors and senior management approached or passed normal retirement age. On top of this, CFGW’s aging shareholder base has been increasingly in search of more stock trading liquidity. The CFGW Board has also monitored the changing community banking landscape in the region, including the decline in potential buyers who could execute on a transaction that would be appealing to CFGW.

Given the changing community banking landscape in the region, regulatory compliance burdens, rising information technology costs, risks associated with director and officer succession planning, and the growing desire for increased CFGW shareholder liquidity, the CFGW Board grew increasingly interested in strategic alternatives that could address these challenges. In reviewing its alternatives, the CFGW Board considered the best ways to maximize CFGW shareholder value, maximize the opportunities for CFGW’s employees and secure the Bank’s long-term future and ability to serve its customers and communities. The CFGW Board carefully considered many strategic alternatives, including: (i) continued organic growth, which would be limited by CFGW’s finite capital resources; (ii) growth through CFGW’s acquisition of smaller institutions, which would be challenging given the lack of viable attractive targets, CFGW’s limited capital resources and the illiquidity of CFGW’s stock; or (iii) merging with a larger bank with more resources to support continued strong financial performance, and provide CFGW shareholders with greater liquidity. In considering these alternatives, the CFGW Board consistently viewed a merger with a larger bank as the alternative that best achieved its strategic objectives. As a result, the CFGW Board and management decided to continue to emphasize organic growth while undertaking strategic initiatives that would maximize the attractiveness of CFGW to potential acquirors. As part of these efforts, early in 2021 the CFGW Board began meeting periodically with Piper Sandler to review developments in the banking industry, including mergers and acquisitions trends, bank performance trends and bank stock valuations. Piper Sandler is a nationally recognized investment banking firm with substantial experience advising financial institutions generally, including with respect to mergers and acquisitions. At the direction of the CFGW Board, Susan Horton, CFGW’s Chairman, CEO and President, began developing relationships with a group of potential merger partners that best aligned with the CFGW Board’s strategic priorities.

Throughout 2021 and 2022, Ms. Horton held in person and telephonic meetings with the CEOs of several potential merger partners, including Randy Chesler, CEO of Glacier, with the intent of learning more about the potential strategic fit between CFGW and the respective merger partners and developing relationships that could help facilitate a potential merger at some point in the future. During this time, Ms. Horton reported to the CFGW Board on the content of the meetings with potential partners and these reports were often accompanied by analytical updates provided by Piper Sandler. In meetings with Ms. Horton, Mr. Chesler expressed Glacier’s interest in pursuing a merger with CFGW and indicated that the most desirable timing for Glacier would be to begin substantive discussions regarding the possibility of a merger in the winter of 2022-2023.

Based on Ms. Horton’s reports and the financial analyses provided by Piper Sandler, Glacier’s unique community banking model and Glacier’s superior financial performance over a long period, among other considerations, the CFGW Board concurred at a meeting on November 10, 2022, that Glacier was the partner

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most capable of structuring a merger that met the strategic objectives of the CFGW Board, namely: to maximize value and liquidity for CFGW shareholders, to maximize the opportunities for CFGW’s employees, and to secure the Bank’s long-term future and ability to serve its customers and communities.

In February 2023, Ms. Horton was contacted by Glacier and invited to a meeting at Glacier’s corporate headquarters. At the meeting on March 7, 2023, Ms. Horton met with Mr. Chesler and other Glacier executives, shared information about CFGW, and learned more about Glacier and its history and approach to mergers and acquisitions and how CFGW and the Bank might benefit from a merger with Glacier. At that meeting Mr. Chesler expressed the interest of Glacier’s board of directors in further exploring an acquisition of CFGW, with the first step being working towards a non-binding letter of intent. On March 10, 2023, Ms. Horton and Piper Sandler met with the CFGW Board to discuss further the potential for a transaction with Glacier as compared to CFGW’s other strategic alternatives, and the CFGW Board agreed to convey to Mr. Chesler their desire to work towards a non-binding letter of intent. Ms. Horton communicated this to Mr. Chesler later that day, and Mr. Chesler indicated that the next step would be for CFGW to provide Glacier with some initial financial information and other information regarding CFGW after CFGW’s first quarter 2023 financial information was available. On March 31, 2023, Mr. Chesler requested that Ms. Horton provide first quarter 2023 and other financial information regarding CFGW. On April 11, 2023, Ms. Horton provided Glacier with the requested information.

In late April and early May 2023, representatives from Glacier’s financial advisor, Keefe, Bruyette & Woods, Inc. (“KBW”), met with Glacier management to discuss the letter of intent and its proposed terms and the potential financial impact of the transaction on Glacier.

On May 8, 2023, Glacier provided CFGW with a non-binding letter of intent which outlined the high-level terms of a proposed merger, including 100% stock consideration and a fixed exchange ratio of 1.0931 Glacier shares in exchange for each share of CFGW. In the days following receipt of the non-binding letter of intent, the financial and legal advisors of CFGW analyzed the financial merits and other significant terms of Glacier’s proposal.

On May 16, 2023, the CFGW Board held a special meeting, along with Piper Sandler and CFGW’s legal counsel, Otteson Shapiro LLP (“Otteson Shapiro”) to review, consider, and discuss Glacier’s proposal. At the meeting, Otteson Shapiro reviewed with the CFGW Board their fiduciary duties in connection with the consideration of the non-binding letter of intent. At the meeting, the CFGW Board considered Glacier’s proposal, CFGW’s stand-alone prospects and the landscape of other potential merger partners for CFGW. The CFGW Board discussed the benefits and drawbacks of Glacier’s proposal and considered how the proposal might be negotiated to better meet the objectives of the CFGW Board. The CFGW Board also discussed the then-current turmoil in the banking industry, including the recent failure of multiple banks and the overall significant decline in bank stock values, and whether it would be possible to meet the objectives of the CFGW Board during such an environment. As part of this consideration, the CFGW Board considered the fact that the Glacier proposal consisted of 100% stock consideration with a fixed exchange ratio, meaning that CFGW shareholders would stand to benefit from a potential recovery in the banking industry through the ownership of Glacier stock, and in addition, that Glacier had a track record of superior financial and stock price performance over the long term. At the conclusion of the meeting, the CFGW Board expressed its sincere interest in Glacier’s proposal, and authorized Ms. Horton, with the assistance of executive management, periodically reviews, assesses,Piper Sandler and discusses AB’s strategic direction, performance,Otteson Shapiro, to clarify and prospects. These reviews and discussions have included from timenegotiate certain terms of the non-binding letter of intent, including but not limited to: requesting an increase in the merger consideration to time, third party advisors, including investment bankers and external legal counsel, and have addressed the potential strategic alternatives that might be available to AB, including organic growth opportunities, potential mergers and acquisitions (including potential acquisition targetsreceived by CFGW shareholders and the saleremoval of AB), and capital planning decisions, all witha stock-price based collar mechanism that could potentially limit the goal of enhancing shareholder value. These reviews and discussions have also included analysesupside to CFGW shareholders during the pendency of the business environment formerger if stock prices in the banking industry increased significantly.

On May 19, 2023, CFGW conveyed to Glacier a package of additional financial institutions,information regarding CFGW that CFGW believed would assist Glacier in refining and improving the terms of its merger proposal. In addition to the financial information, CFGW shared with Glacier a list of requested clarifications and

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amendments to the non-binding letter of intent, including technology initiatives and investments,but not limited to an increase in the impact of low interest rates, the evolution of community banking, and talent acquisition and retention. Economic outlook nationally and locally, the regulatory and compliance environment, financial institution industry trends, peer comparisons, ongoing consolidation among financial institutions,merger consideration and the benefits and risks of continued operation as a standalone company have also been considered. Factors assessed in connection with these reviews have included the risks and opportunities 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 financial institutions and has regularly updated the AB Board regarding such discussions.

Randall M. Chesler, President and Chief Executive Officer of Glacier, and Len E. Williams, President and Chief Executive Officer of AB, have lengthy careers in the financial institutions industry and have known each other professionally for the last two to three 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 membersremoval of the Gunther family and their related entities (the “Section 13D Group”) executed a shareholder agreement on January 28, 2020 and jointly filed a Schedule 13D with the 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.

To avoid potential conflicts of interest and to advance the best 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 X regarding a potential acquisition.

Duringstock-price based collar mechanism. Over the course of the next several months, at regularly-scheduled Board meetingsfive days, representatives of CFGW and through periodic communications withGlacier discussed and negotiated the AB Board, executive management provided the AB Board updates on unsolicited

implied value of the merger consideration relative to bank stock values in general along with an overview of some of the variables that might impact CFGW’s ability to pay a pre-closing dividend or result in a downward adjustment in the exchange ratio, namely CFGW’s forecast earnings, CFGW’s expected transaction expenses and potential changes in CFGW’s accumulated other comprehensive income related to its investment portfolio. The proposed timing and strategy for approaching the Section 13D Group regarding the proposed transaction was also discussed. TheCFGW Board discussed the overall strength and viabilitythat, as part of the proposed transaction taking into account the fluctuation in the implied valuationterms, CFGW would benefit from keeping certain of its transaction-related expenses as a resultlow as possible. The payout of changes in stock prices, and the AB Board instructedcertain existing 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 tocontracts that would 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 the 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 merger 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, the voting agreements which included key members of the Section 13D Group and the Davis 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 accompanying legal standards. Jones Day proceeded to review in detail with the AB Board the terms of the merger agreement, including the terms of various ancillary documents. KBW then reviewed the financial aspects of the proposed transaction, including the financial analyses with respect to the proposed transaction that KBW performed, and KBW rendered to the AB Board an opinion, initially rendered verbally and confirmed in a written opinion dated May 17, 2021, to the effect

merger agreement and related transaction documents, and representatives of Piper Sandler reviewed the financial aspects of the proposed merger and responded to questions by the CFGW and the Bank Boards of Directors. Additionally, Piper Sandler delivered its oral opinion (commonly referred to as the “fairness opinion”), which was confirmed in writing later on August 8, 2023, to the effect that, as of such date and subject to the procedures followed, assumptions made, matters considered, and qualifications and limitations on the review undertaken by Piper Sandler as set forth in its opinion, the per share stock consideration was fair, from a financial point of view, to the Glacier Board on May 18, 2021, AB and Glacier executed the merger agreement, eachholders of CFGW common stock. After further discussion among the directors and each ofCFGW’s advisors, including with respect to 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 Reasonsfactors described in “Reasons for the Merger

After careful consideration, at a meeting held on May 17, 2021, — CFGW” the ABCFGW Board unanimously determined that the merger agreement, includingand the merger of the Bank into Glacier Bank, isagreement were advisable, and in the best interests of, ABCFGW and AB’sits shareholders, and approvedthe Bank, and adoptedunanimously approved the merger agreement.