GENERALGENERAL DESCRIPTION OF SECURITIES WE MAY SELL

We, directly or through agents, dealers or underwriters that we may designate, may offer and sell, from time to time, up to $125,000,000 (or the equivalent in one or more foreign currency units)$120,000,000 aggregate initial offering price of:

We may offer and sell these securities either separately, together, or together,as units, each on terms to be determined at the time of the offering. We may issue debt securities and/or preferred stock that are exchangeable for and/or convertible into common stock or any of the other securities that may be sold under this prospectus. When particular securities are offered, a supplement to this prospectus will be delivered with this prospectus, which will describe the terms of the offering and sale of the offered securities.

DESCRIPTIONOFDESCRIPTION OF CAPITAL STOCK

We are authorized to issue 15,000,000 shares of common stock, par value $0.01 per share, and 10,000,000 shares of preferred stock, par value $0.01, per share. As of April 15, 2009,December 31, 2016, there were 9,236,4939,601,011 shares of common stock outstanding, and no shares of preferred stock outstanding.

This section describes the general terms and provisions of the common stock that we may offer separately, upon conversion or exchange of a debt security or upon conversion or exchange of our preferred stock, as well as the general terms and provisions of our preferred stock that we may issue separately or upon conversion or exchange of a debt security. The following description of our common stock and preferred stock is summarized from, and qualified in its entirety by reference to, our Second Restated Articles of Incorporation, as amended, a copy of which has been filed with the SEC and is incorporated by reference as an exhibit to the registration statement of which this prospectus is a part. This summary is not intended to give full effect to provisions of statutory or common law. We urge you to review the following documents because they, and not this summary, define your rights as a holder of shares of common stock:

Terms of Common Stock

Holders of common stock are entitled to receive such dividends as may from time to time be declared by our board of directors out of funds legally available therefor, subject to any preferential dividend rights granted to the holders of any outstanding series of Preferredpreferred stock. We currently intend to retain our earnings for use in our business and, therefore, we do not anticipate paying any cash dividends in the foreseeable future. We have never declared or paid any cash dividends on our capital stock. In the future, the decision to pay any cash dividends will depend upon our results of operations, financial condition and capital expenditure plans, as well as such other factors as our board of directors, in its sole discretion, may consider relevant. Holders of common stock are entitled to one vote per share on all matters on which the holders of common stock are entitled to vote and do not have any cumulative voting rights. Holders of common stock have no preemptive, conversion, redemption or sinking fund rights. In the event of our liquidation, dissolution or winding up, holders of common stock are entitled to share equally and ratably in our assets, if any, remaining after the payment of all of our debts and liabilities and the liquidation preference of any outstanding class or series of preferred stock. The outstanding shares of common stock are, and the shares of common stock offered by us hereby when issued will be, fully paid and nonassessable. The rights, preferences and privileges of holders of common stock are subject to any series of preferred stock that we may issue in the future as described below.

Our common stock is listed on the Nasdaq Global Select Market under the symbol “NWPX.”

Terms of Preferred Stock

Our

We may issue shares of our preferred stock from time to time, in one or more series. Under our articles of incorporation, our board of directors is authorizedhas the authority, without further action by shareholders, to issue ourdesignate up to 10,000,000 shares of preferred stock, $0.01 par value per share, in one or more series and to fix the rights, preferences, privileges, qualifications and restrictions granted to or imposed upon the preferred stock, including but not limited to dividend rights, conversion rights, voting rights;rights, rights and terms of redemption, liquidation preference and sinking fund terms, any or all of which may be greater than the designations, preferences, limitations and relative rights of any series with respect to the rate of dividend, the price, the terms and conditions of redemption; the amounts payable in the event of voluntary or involuntary liquidation; sinking fund provisions for redemption or purchase of a series; and the terms and conditions on which a series may be converted.common stock.

If we offerissue preferred stock, we will filefix the terms of the preferred stock with the SEC and the prospectus supplement and/or other offering material relating to that offering will include a description of the specific terms of the offering, including the following specific terms:

We urge you to read the prospectus supplement related to any series of preferred stock we may offer, as well as the complete certificate of designation that contains the terms of the applicable series of preferred stock. It is not possible to state the actual effect of the issuance of any shares of preferred stock upon the rights of holders of our common stock until our board of directors determines the specific rights of the holders of the preferred stock. However, these effects might include:

Preferred Stock Purchase Rights

We have

In connection with the rights agreement that we entered into with Mellon Investor Services LLC as rights agent on June 18, 2009, our board of directors designated 150,000 shares of preferred stock as series A junior participating preferred stock (“Series A Preferred Stock”). In connection with the rights agreement, pursuant to whicha dividend was declared of one preferred stock purchase right for each outstanding share of common stock also represents ownership of one preferred stock purchase right.stock. Each such right entitles the registered holder to purchase from us one one-hundredth of a share of Series A Junior Participating Preferred Stock at a purchase price of $83.00 per one one-hundredth share, subject to adjustment. Each share of common stock that we issue prior to the expiration of the rights agreement will have attached one right. Under circumstances described below, the rights will entitle the holder of the rights to purchase additional shares of our common stock. Unless the context requires otherwise, reference in this prospectus to our common stock includes the accompanying rights.

Currently, the rights are not exercisable and trade with our common stock. The rights will only become exercisable if a person or group has acquired 15% or more of our outstanding common stock in the aggregate, or announced an intention to acquire 15% or more of our outstanding common stock in the aggregate. If the rights become exercisable, each holder of a right, other than the acquiring party, will be entitled to purchase, at the right’s then-current exercise price, shares of our common stock having a market value of two times the exercise

price. If another corporation acquires us after a party acquires 15% or more of our common stock, then each holder of a right will be entitled to receive the acquiring corporation’s common shares having a market value of two times the exercise price. The rights generally may be redeemed at a price of $0.01 per right until a party acquires 15% or more of our common stock, and after that time may be exchanged for one share of our common stock per right until a party acquires 50% or more of our common stock. The rights will expire on June 28, 2009,2019, unless the rights are earlier redeemed or the rights agreement is amended. The rights do not have voting or dividend rights and, until they become exercisable, have no dilutive effect on our earnings.

As of December 31, 2016, no shares of Series A Preferred Stock were outstanding and we have no present plan to issue any shares of Series A Preferred Stock.

The description and terms of the rights are set forth in a rights agreement, dated June 28, 1999,18, 2009, between us and BNY Mellon ShareownerInvestor Services (formerly ChaseMellon Shareholder Services, L.L.C.)LLC as rights agent, a copy of which has been filed with the SEC and is incorporated by reference as an exhibit to the registration statement of which this prospectus is a part. The foregoing summary of the terms of the rights agreement is not complete and is qualified by reference to the rights agreement.

Anti-takeover Effects of Certain Provisions of Oregon Law, the Articles and Bylaws

We are subject to the Oregon Business Combination Act. The Business Combination Act generally provides that in the event a person or entity acquires 15% or more of the voting stock of an Oregon corporation, thereby becoming an “interested shareholder,” the corporation and the interested shareholder, or any affiliated entity, may not engage in certain business combination transactions for a period of three years following the date the person became an interested shareholder. Business combination transactions for this purpose include:

These restrictions are not applicable if:

Our Second Restated Articles of Incorporation, as amended, contain provisions that (1)(i) classify the board of directors into three classes, each of which serves for a three-year term with one class elected each year, (2)(ii) provide that directors may be removed by shareholders only for cause and only upon the affirmative vote of 75% of the outstanding shares of common stock, and (3)(iii) permit the board of directors to issue preferred stock in one or more series and to fix the number of shares constituting any such series, the voting powers and all other rights and preferences of any such series, without any further vote or action by our shareholders.shareholders, and (iv) require the approval of the holders of not less than sixty-seven percent (67%) of the outstanding shares of the Company for any agreement of merger or consolidation, sale of all or substantially all of the Company’s assets or dissolution or liquidation of the Company.

Our Third Amended and Restated Bylaws contain provisions requiring that (i) any action to be taken by our shareholders must be effected at a duly called annual or special meeting of shareholders, except where such action is taken by the unanimous written consent of all shareholders entitled to vote on such action; and (ii) any shareholder seeking to present proposals before a meeting of shareholders or to nominate candidates for election to the board of directors at a meeting of shareholders must provide notice in writing in a timely manner in advance of any such action.

The staggered terms for directors, the provisions allowing the removal of directors only for cause, the availability of preferred stock for issuance without shareholder approval, the rights agreement, the limitation on shareholder action by less than unanimous written consent, and the shareholder rights planadvance notice requirement for proposals and nominations by shareholders may have the effect of lengthening the time required for a person to acquire control of us through a proxy contest or the election of a majority of the board of directors and may deter any potential unfriendly offers or other efforts

to obtain control. This could deprive our shareholders of opportunities to realize a premium for their common stock and could make removal of incumbent directors more difficult. At the same time, these provisions may have the effect of inducing any persons seeking control of us to negotiate terms acceptable to the board of directors.

Transfer Agent

The transfer agent and registrar for our common stock is BNY Mellon Shareowner Services.Computershare Trust Company, N.A.

DESCRIPTION OFDESCRIPTION OF WARRANTS

We may issue warrants for the purchase of common stock, preferred stock or preferred stock.debt securities. Warrants may be issued independently or together with any other securities pursuant to any prospectus supplement and may be attached to or separate from such securities. Each series of warrants will be issued under a separate warrant agreement between us and the warrant recipient or, if the recipients are numerous, a warrant agent identified in the applicable prospectus supplement. The warrant agent, if engaged, will act solely as our agent in connection with the warrants of such series and will not assume any obligation or relationship of agency or trust for or with any holders or beneficial owners of warrants. Further terms of any warrants to be issued and a description of the warrants andmaterial provisions of the applicable warrant agreementsagreement will be set forth in the applicable prospectus supplement.

The applicable prospectus supplement will describe the terms of any warrants in respect of which this prospectus is being delivered, including, where applicable, the following:

You should review the section captioned “Description of Capital Stock” for a general description of the common stock and preferred stock that may be issued upon the exercise of the warrants.

DESCRIPTIONOFDESCRIPTION OF DEBT SECURITIES

This section describes

The following description, together with the additional information we include in any applicable prospectus supplement, summarizes certain general terms and provisions of the debt securities that we may issue. As usedoffer under this prospectus. When we offer to sell a particular series of debt securities, we will describe the specific terms of the series in a supplement to this prospectus. We will also indicate in the supplement to what extent the general terms and provisions described in this prospectus the term “debt securities” means the debentures, bonds, notes and other evidencesapply to a particular series of indebtedness that we may issue from time to time. debt securities.

The debt securities will be issued under an indenture between us and a third party to be identified therein as trustee. We have summarized select portions of the indenture below. The summary is not complete. The form of the indenture has been filed as an exhibit to the registration statement and you should read the indenture for provisions that may be seniorimportant to you. Capitalized terms used in the summary and not defined herein have the meanings specified in the indenture.

General

The terms of each series of debt securities senior subordinatedwill be established by or pursuant to a resolution of our board of directors and set forth or determined in the manner provided in a resolution of our board of directors, in an officer’s certificate or by a supplemental indenture. The particular terms of each series of debt securities will be described in a prospectus supplement relating to such series.

We can issue an unlimited amount of debt securities under the indenture that may be in one or subordinated debt securities. We may also issue convertiblemore series with the same or exchangeable debt securities.various maturities, at par, at a premium or at a discount. We will set forth in a prospectus supplement relating to any series of debt securities being offered, the particularaggregate principal amount and the following terms of the debt securities, if applicable:

We may issue debt securities that provide for an amount less than their stated principal amount to be due and payable upon declaration of acceleration of their maturity pursuant to the terms of the indenture. We will provide you with information on the United States federal income tax considerations and other special considerations applicable to any of these debt securities in the applicable prospectus supplement.

Transfer and Exchange

Each debt security will be represented by either one or more global securities registered in the name of a depositary (we will refer to any debt security represented by a global debt security as a “book-entry debt security”), or a certificate issued in definitive registered form (we will refer to any debt security represented by a certificated security as a “certificated debt security”) as set forth in the applicable prospectus supplement.

Certificated Debt Securities. You may transfer or exchange certificated debt securities at any office we offermaintain for this purpose in accordance with the terms of the indenture. No service charge will be made for any transfer or exchange of certificated debt securities, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with a transfer or exchange. You may effect the transfer of certificated debt securities and the right to receive the principal of, premium, if any, and interest on certificated debt securities only by surrendering the certificate representing those certificated debt securities and either reissuance by us or the trustee of the certificate to the new holder or the issuance by us or the trustee of a new certificate to the new holder.

Global Debt Securities and Book-Entry System. Each global debt security representing book-entry debt securities will be deposited with, or on behalf of, a depositary, registered in the name of the depositary or a nominee of the depositary, and follow the applicable procedures of the depositary. Please see “Forms of Securities.”

Consolidation, Merger and Sale of Assets

We may not consolidate with or merge with or into, or convey, transfer or lease all or substantially all of our properties and assets to any person (a “successor person”) unless:

Notwithstanding the above, any of our subsidiaries may consolidate with, merge into or transfer all or part of its properties to us.

Events of Default

“Event of Default” means with respect to any series of debt securities, any of the following:

No Event of Default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an Event of Default with respect to any other series of debt securities. The occurrence of certain Events of Default or an acceleration under the indenture may constitute an event of default under certain indebtedness of ours or our subsidiaries outstanding from time to time.

If an Event of Default with respect to debt securities of any series at the time outstanding occurs and is continuing, then the trustee or the holders of not less than 25% in principal amount of the outstanding debt securities of that series may, by a notice in writing to us (and to the trustee if given by the holders), declare to be due and payable immediately the principal of (or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) and accrued and unpaid interest, if any, on all debt securities of that series. In the case of an Event of Default resulting from certain events of bankruptcy, insolvency or reorganization, the principal (or such specified amount) of and accrued and unpaid interest, if any, on all outstanding debt securities will become and be immediately due and payable without any declaration or other act on the part of the trustee or any holder of outstanding debt securities. At any time after a declaration of acceleration with respect to debt securities of any series has been made, but before a judgment or decree for payment of the money due has been obtained by the trustee, the holders of a majority in principal amount of the outstanding debt securities of that series may rescind and annul the acceleration if all Events of Default, other than the non-payment of accelerated principal and interest, if any, with respect to debt securities of that series, have been cured or waived as provided in the indenture. We refer you to the prospectus supplement relating to any series of debt securities that are discount securities for the particular provisions relating to acceleration of a portion of the principal amount of such discount securities upon the occurrence of an Event of Default.

No holder of any debt security of any series will have any right to institute any proceeding, judicial or otherwise, with respect to the indenture or for the appointment of a receiver or trustee, or for any remedy under the indenture, unless:

Notwithstanding any other provision in the indenture, the holder of any debt security will have an absolute and unconditional right to receive payment of the principal of, premium and any interest on that debt security on or after the due dates expressed in that debt security and to institute suit for the enforcement of payment.

The indenture requires us, within 120 days after the end of our fiscal year, to furnish to the trustee a statement as to compliance with the indenture. If a Default or Event of Default occurs and is continuing with respect to the securities of any series and if it is known to a responsible officer of the trustee, the trustee shall deliver (or electronically deliver while Notes are in global form) to each Security holder of the securities of that series notice of a Default or Event of Default within 90 days after it occurs or, if later, after a responsible officer of the trustee has knowledge of such Default or Event of Default. The indenture provides that the trustee may withhold notice to the holders of debt securities of any series of any Default or Event of Default (except in payment on any debt securities of that series) with respect to debt securities of that series if the trustee determines in good faith that withholding notice is in the interest of the holders of those debt securities.

Modification and Waiver

We and the trustee may modify, amend or supplement the indenture or the debt securities of any series without the consent of any holder of any debt security:

We may also modify and amend the indenture with the consent of the holders of at least a majority in principal amount of the outstanding debt securities of each series affected by the modifications or amendments. We may not make any modification or amendment without the consent of the holders of each affected debt security then outstanding if that amendment will:

Except for certain specified provisions, the holders of at least a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all debt securities of that series waive our compliance with provisions of the indenture. The holders of a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all the debt securities of such series waive any past default under the indenture with respect to that series and its consequences, except a default in the payment of the principal of, any premium or any interest on any debt security of that series; provided, however, that the holders of a majority in principal amount of the outstanding debt securities of any series may rescind an acceleration and its consequences, including any related payment default that resulted from the acceleration.

Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

Legal Defeasance. The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, we may be discharged from any and all obligations in respect of the debt securities of any series (subject to certain exceptions). We will be so discharged upon the deposit with the trustee, in trust, of money and/or U.S. government obligations or, in the case of debt securities denominated in a prospectus supplement. Debt securities maysingle currency other than U.S. Dollars, government obligations of the government that issued or caused to be issued such currency, that, through the payment of interest and principal in accordance with their terms, will provide money or U.S. government obligations in an amount sufficient in the opinion of a nationally recognized firm of independent public accountants or investment bank to pay and discharge each installment of principal, premium, if any, and interest on and any mandatory sinking fund payments in respect of the debt securities of that series on the stated maturity of those payments in accordance with the terms of the indenture and those debt securities.

This discharge may occur only if, among other things, we have delivered to the trustee an opinion of counsel stating that we have received from, or there has been published by, the United States Internal Revenue Service a ruling or, since the date of execution of the indenture, there has been a change in the applicable United States federal income tax law, in either case to the effect that, and based thereon such opinion shall confirm that, the beneficial owners of the debt securities of that series will not recognize income, gain or loss for United States federal income tax purposes as a result of the deposit, defeasance and discharge and will be subject to United States federal income tax on the same amounts and in the same manner and at the same times as would have been the case if the deposit, defeasance and discharge had not occurred.

Defeasance of Certain Covenants. The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, upon compliance with certain conditions:

The conditions include:

Governing Law

The indenture and the debt securities, including any claim or controversy arising out of or relating to the indenture or the securities, will be governed by the laws of the State of New York.

DESCRIPTIONOFUNITS

We may issue units consisting of any combination of the other types of securities offered under an indenture (whichthis prospectus in one or more series. We may evidence each series of units by unit certificates that we referwill issue under a separate agreement. We may enter into unit agreements with a unit agent. Each unit agent will be a bank or trust company that we select. We will indicate the name and address of the unit agent in the applicable prospectus supplement relating to hereina particular series of units.

The following description, together with the additional information included in any applicable prospectus supplement, summarizes the general features of the units that we may offer under this prospectus. You should read any prospectus supplement and any free writing prospectus that we may authorize to be provided to you related to the series of units being offered, as well as the complete unit agreements that contain the terms of the units. Specific unit agreements will contain additional important terms and provisions and we will file as an Indenture) entered into between us and a trustee to be named therein.

The Indenture or forms of Indentures, if any, will be filed as exhibitsexhibit to the registration statement of which this prospectus is a part. The statements and descriptions in this prospectuspart, or in any prospectus supplement regarding provisions of the Indentures and debt securities are summaries thereof, do not purport to be complete and are subject to, and are qualified in their entiretywill incorporate by reference to, all of the provisions of the Indentures (and any amendments or supplementsfrom another report that we may enter into from time to time which are permitted under each Indenture) and the debt securities, including the definitions therein of certain terms.

General

Unless otherwise specified in a prospectus supplement, the debt securities will be direct secured or unsecured obligations of our company. The senior debt securities will rank equally with any of our other unsecured senior and unsubordinated debt. The subordinated debt securities will be subordinate and junior in right of payment to any senior indebtedness.

We may issue debt securities from time to time in one or more series, in each casefile with the same or various maturities, at par or at a discount. Unless indicated in a prospectus supplement,SEC, the form of each unit agreement relating to units offered under this prospectus.

If we may issue additional debt securities of a particular series without the consent of the holders of the debt securities of such series outstanding at the time of the issuance. Any such additional debt securities, together with all other outstanding debt securitiesoffer any units, certain terms of that series will constitute a single series of debt securities under the applicable Indenture andunits will be equal in ranking.

Terms of Debt Securities

Each prospectus supplement will describe the terms relating to the specific series of debt securities being offered. These terms will include some or all of the following:

Unless otherwise specified in the applicable prospectus supplement, including, without limitation, the following, as applicable:

FORMSOF SECURITIES

Each debt security, warrant and unit will be represented either by a certificate issued in definitive form to a particular investor or by one or more global securities representing the entire issuance of securities. Certificated securities in definitive form and global securities will not be listed on anyissued in registered form. Definitive securities exchange. Holdersname you or your nominee as the owner of the security, and in order to transfer or exchange these securities or to receive payments other than interest or other interim payments, you or your nominee must physically deliver the securities to the trustee, registrar, paying agent or other agent, as applicable. Global securities name a depositary or its nominee as the owner of the debt securities, warrants or units represented by these global securities. The depositary maintains a computerized system that will reflect each investor’s beneficial ownership of the securities through an account maintained by the investor with its broker/dealer, bank, trust company or other representative, as we explain more fully below.

We may presentissue the registered debt securities, for exchange or transferwarrants and units in the manner described in the applicable prospectus supplement. Except as limited by the applicable Indenture,form of one or as otherwise providedmore fully registered global securities that will be deposited with a depositary or its nominee identified in the applicable prospectus supplement we will provide these services without charge, other than any tax or other governmental charge payable in connection with the exchange or transfer.

Debt securities may bear interest at a fixed rate or a variable rate as specifiedand registered in the prospectus supplement.name of that depositary or nominee. In addition, if specifiedthose cases, one or more registered global securities will be issued in a denomination or aggregate denominations equal to the portion of the aggregate principal or face amount of the securities to be represented by registered global securities. Unless and until it is exchanged in whole for securities in definitive registered form, a registered global security may not be transferred except as a whole by and among the depositary for the registered global security, the nominees of the depositary or any successors of the depositary or those nominees.

If not described below, any specific terms of the depositary arrangement with respect to any securities to be represented by a registered global security will be described in the prospectus supplement werelating to those securities. We anticipate that the following provisions will apply to all depositary arrangements.

Ownership of beneficial interests in a registered global security will be limited to persons, called participants, that have accounts with the depositary or persons that may sell debthold interests through participants. Upon the issuance of a registered global security, the depositary will credit, on its book-entry registration and transfer system, the participants’ accounts with the respective principal or face amounts of the securities bearing no interestbeneficially owned by the participants. Any dealers, underwriters or interest at a rate that at the time of issuance is below the prevailing market rate, or at a discount below their stated principal amount. We will describeagents participating in the applicable prospectus supplement any special federal income tax considerations applicable to these discounted debt securities.

We may issue debtdistribution of the securities withwill designate the principal amount payable on any principal payment date, or the amount of interest payable on any interest payment date,accounts to be determinedcredited. Ownership of beneficial interests in a registered global security will be shown on, and the transfer of ownership interests will be effected only through, records maintained by referringthe depositary, with respect to oneinterests of participants, and on the records of participants, with respect to interests of persons holding through participants. The laws of some states may require that some purchasers of securities take physical delivery of these securities in definitive form. These laws may impair your ability to own, transfer or more currency exchange rates, commodity prices, equity indicespledge beneficial interests in registered global securities.

So long as the depositary, or other factors. Holdersits nominee, is the registered owner of such debta registered global security, that depositary or its nominee, as the case may be, will be considered the sole owner or holder of the securities mayrepresented by the registered global security for all purposes under the applicable indenture, warrant agreement or unit agreement. Except as described below, owners of beneficial interests in a registered global security will not be entitled to have the securities represented by the registered global security registered in their names, will not receive or be entitled to receive physical delivery of the securities in definitive form and will not be considered the owners or holders of the securities under the applicable indenture, warrant agreement or unit agreement. Accordingly, each person owning a principal amountbeneficial interest in a registered global security must rely on the procedures of the depositary for that registered global security and, if that person is not a participant, on the procedures of the participant through which the person owns its interest, to exercise any principal payment date,rights of a holder under the applicable indenture, warrant agreement or unit agreement. We understand that under existing industry practices, if we request any action of holders or if an owner of a beneficial interest in a registered global security desires to give or take any action that a holder is entitled to give or take under the applicable indenture, warrant agreement, guaranteed trust preferred security or unit agreement, the depositary for the registered global security would authorize the participants holding the relevant beneficial interests to give or take that action, and the participants would authorize beneficial owners owning through them to give or take that action or would otherwise act upon the instructions of beneficial owners holding through them.

Principal, premium, if any, and interest payments on debt securities, and any interestpayments to holders with respect to warrants or units, represented by a registered global security registered in the name of a depositary or its nominee will be made to the depositary or its nominee, as the case may be, as the registered owner of the registered global security. None of the Company, the trustee, the warrant agents, the unit agents or any other agent of the Company, agent of the trustee or agent of the warrant agents or unit agents will have any responsibility or liability for any aspect of the records relating to payments made on account of beneficial ownership interests in the registered global security or for maintaining, supervising or reviewing any records relating to those beneficial ownership interests.

We expect that the depositary for any of the securities represented by a registered global security, upon receipt of any payment date, that are greater or less than the amount of principal, orpremium, interest otherwise payable on such dates, depending upon the value on such dates of applicable currency, commodity, equity index or other factors. The applicable prospectus supplementdistribution of underlying securities or other property to holders on that registered global security, will contain informationimmediately credit participants’ accounts in amounts proportionate to their respective beneficial interests in that registered global security as shown on the records of the depositary. We also expect that payments by participants to howowners of beneficial interests in a registered global security held through participants will be governed by standing customer instructions and customary practices, as is now the case with the securities held for the accounts of customers in bearer form or registered in “street name,” and will be the responsibility of those participants.

If the depositary for any of these securities represented by a registered global security is at any time unwilling or unable to continue as depositary or ceases to be a clearing agency registered under the Exchange Act, and a successor depositary registered as a clearing agency under the Exchange Act is not appointed by us within 90 days, we will determineissue securities in definitive form in exchange for the amount of principalregistered global security that had been held by the depositary. Any securities issued in definitive form in exchange for a registered global security will be registered in the name or interest payable on any date, as well asnames that the currencies, commodities, equity indicesdepositary gives to the relevant trustee, warrant agent, unit agent or other factorsrelevant agent of ours or theirs. It is expected that the depositary’s instructions will be based upon directions received by the depositary from participants with respect to whichownership of beneficial interests in the amount payable onregistered global security that date relates and certain additional tax considerations.

PLANOFPLAN OF DISTRIBUTION

We may sell the securities covered by this prospectus from time to time in any manner permitted under the Securities Act. Registration of the securities covered by this prospectus does not mean, however, that those securities will necessarily be offered or sold.

We may sell the securities separately or together:

●     directly to investors;

●     through one or more underwriters or dealers in a public offering and sale by them;

●     through dealers; or

●     through agents.

We may also make direct sales through subscription rights distributed to our shareholders on a pro rata basis, which may or may not be transferable. In any distribution of subscription rights to shareholders, if all of the following waysunderlying securities are not subscribed for, we may then sell the unsubscribed securities directly to third parties or may engage the services of one or more underwriters, dealers or agents, including standby underwriters, to sell the unsubscribed securities to third parties.

We may sell the securities from time to time:

Any dealer or agent, in addition to any underwriter, may be deemed to be an underwriter within the meaning of the Securities Act, and any discounts or commissions they receive from us and any profit on the resale of the offered securities by them may be treated as underwriting discounts and commissions under the Securities Act. The terms of the offering of the securities with respect to which this prospectus is being delivered will be set forth in the applicable prospectus supplement and will include:

If underwriters are used in the sale of any securities, suchthe securities willmay be acquired by the underwriters for their own account and may be resold from time to time in one or more of the transactions including negotiated transactions, atdescribed above. Any underwritten offering may be on a fixed public offering pricebest efforts or at varying prices determined at the time of sale.firm commitment basis. The securities may be either offered to the public either through underwriting syndicates represented by managing underwriters, or directly by one or more underwriters acting alone. Unless otherwise set forth inunderwriters. Generally, the applicable prospectus supplement, theunderwriters’ obligations of the underwriters to purchase the securities described in the applicable prospectus supplement will be subject to certain conditions precedent and the underwriters will be obligated to purchase all suchof the securities if they purchase any are so purchased by them.of the securities. We may use underwriters with whom we have a material relationship. We will describe in the prospectus supplement, naming the underwriter, the nature of any such relationship.

In any sale of the securities, underwriters or agents may receive compensation from us or from purchasers of the securities, for whom they may act as agents, in the form of discounts, concessions or commissions. Underwriters may sell the securities to or through dealers, and such dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or commissions from the purchasers for whom they may act as agents. Underwriters, dealers and agents that participate in the distribution of the securities may be deemed to be underwriters under the Securities Act, and any discounts or commissions they receive from us and any profit on the resale of securities they realize may be deemed to be underwriting discounts and commissions under the Securities Act. Any initial public offering price and any discounts or concessions allowed or reallowedre-allowed or paid to dealers may be changed from time to time.

The

Each time we sell securities, may be sold directly by us or through agents designated by us from time to time. Any agents involved inwe will describe the offer or salemethod of distribution of the securities in respect of which thisthe prospectus is being delivered, and any commissions payable by ussupplement relating to such agents, will be set forth in the applicable prospectus supplement. Unless otherwise indicated in thetransaction. The applicable prospectus supplement any such agent will, be acting on a best efforts basis for the periodwhere applicable:

IfWe may authorize underwriters, dealers are utilized in the sale of any securities, we will sell the securities to the dealers, as principals. Any dealer may resell the securities to the public at varying prices to be determined by the dealer at the time of resale. The name of any dealer and the terms of the transaction will be set forth in the prospectus supplement with respect to the securities being offered.

Securities may also be offered and sold, if so indicated in the applicable prospectus supplement, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more firms, which we refer to herein as the “remarketing firms,” acting as principals for their own accounts or as our agents as applicable. Any remarketing firm will be identified and the terms of its agreement, if any, with us and its compensation will be described in the applicable prospectus supplement. Remarketing firms may be deemed to be underwriters, as that term is defined in the Securities Act, in connection with the securities remarketed thereby.

If so indicated in the applicable prospectus supplement, we will authorize agents, underwriters or dealers to solicit offers by certain specified institutionspurchasers to purchase the securities to which this prospectus and the applicable prospectus supplement relates from us at the public offering price set forth in the applicable prospectus supplement plus, if applicable, accrued interest pursuant to delayed delivery contracts providing for payment and delivery on a specified date in the future. SuchThe contracts will be subject only to those conditions set forth in the applicable prospectus supplement, and the applicable prospectus supplement will set forth the commission payableany commissions we pay for solicitation of suchthese contracts.

We may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions. If so, the third party may use securities pledged by us or borrowed from us or others to settle those sales or to close out any related open borrowings of stock, and may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third partiesparty in such sale transactions will be underwritersan underwriter and will be identified in the applicable prospectus supplement (oror in a post-effective amendment).amendment.

To facilitate

Underwriters, dealers and agents may be entitled to indemnification by us against certain civil liabilities, including liabilities under the offeringSecurities Act, or to contribution with respect to payments made by the underwriters, dealers or agents, under agreements between us and the underwriters, dealers and agents.

We may grant underwriters who participate in the distribution of securities certain persons participatingan option to purchase additional securities to cover over-allotments, if any, in connection with the distribution.

Unless otherwise specified in the offeringrelated prospectus supplement, all securities we offer, other than common stock, will be new issues of securities with no established trading market. Any underwriters may make a market in these securities, but will not be obligated to do so and may discontinue any market making at any time without notice. Any common stock sold pursuant to a prospectus supplement will be listed for trading on the Nasdaq Global Select Market or other principal market for our common stock. We may apply to list any series of preferred stock, debt securities or warrants on an exchange, but we are not obligated to do so. Therefore, there may not be liquidity or a trading market for any series of securities.

Any underwriter may engage in over-allotment transactions, that stabilize, maintain, or otherwise affect the price of the securities. These may include over-allotment, stabilization, syndicate short coveringstabilizing transactions, short-covering transactions and penalty bids.bids in accordance with Regulation M under the Exchange Act. Over-allotment involves sales in excess of the offering size, which createscreate a short position. Stabilizing transactions involvepermit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum. Syndicate shortShort covering transactions involve purchases of the securities in the open market after the distribution has beenis completed in order to cover syndicate short positions. Penalty bids permit the underwriters to reclaim a selling concessionsconcession from dealersa dealer when the securities originally sold by the dealersdealer are purchased in a covering transactionstransaction to cover syndicate short positions. These transactions, if commenced,Those activities may be discontinued bycause the underwriters at any time.

During such time as we may be engaged in a distributionprice of the securities covered by this prospectus we are required to comply with Regulation M promulgated underbe higher than it would otherwise be. If commenced, the Securities Exchange Act of 1934. With certain exceptions, Regulation M precludes us,underwriters may discontinue any affiliated purchasers, and any broker-dealer or other person who participates in such distribution from bidding for or purchasing, or attempting to induce any person to bid for or purchase, any security which is the subject of the distribution untilactivities at any time. We make no representation or prediction as to the entire distribution is complete. Regulation M also restricts bidsdirection or purchases made in order to stabilizemagnitude of any effect that such transactions may have on the price of the securities. For a security in connection withdescription of these activities, see the distribution of that security.

Agents, dealers, underwriters and remarketing firms may be entitled, under agreements entered into with us, to indemnification by us against certain civil liabilities, including liabilitiesinformation under the Securities Act,heading “Underwriting” or to contribution to payments they“Plan of Distribution” in the applicable prospectus supplement.

Underwriters, broker-dealers or agents who may be required to makebecome involved in respect thereof. Agents, dealers, underwriters and remarketing firmsthe sale of the common stock may be customers of, engage in transactions with orand perform other services for us in the ordinary course of business.their business for which they receive compensation.

Each series of

To comply with applicable state securities laws, the securities offered by this prospectus will be a new issue and, other than our common stock, which is listed on the Nasdaq Global Select Market, willsold, if necessary, in such jurisdictions only through registered or licensed brokers or dealers. In addition, securities may not be sold in some states unless they have no established trading market. We may elect to list any series of securities on an exchange, and in the case of the common stock, on any additional exchange, but, unless

otherwise specifiedbeen registered or qualified for sale in the applicable prospectus supplement, we shall not be obligated to do so. Any underwriters to whom securities are sold for public offeringstate or an exemption from the registration or qualification requirement is available and sale may make a market in the securities, but the underwriters will not be obligated to do so and may discontinue any market making at any time without notice. The securities may or may not be listed on a national securities exchange or a foreign securities exchange. No assurance can be given as to the liquidityis complied with.

The place, time of delivery and other terms of the offered securities will be described in the applicable prospectus supplement.

LEGALLEGAL MATTERS

Except as otherwise provided in any applicable prospectus supplement, Ater Wynne LLP, Portland, Oregon, will pass upon the validity of the securities being offered hereby.

EXPEEXPERTSRTS

The 2008 and 2007 financial statements and related financial statement schedule and the retrospective adjustments to the 2006consolidated financial statements and financial statement disclosuresschedule of Northwest Pipe Company as of December 31, 2016, and subsidiaries (the “Company”) incorporatedfor the year then ended, appearing in this Prospectus by reference from theNorthwest Pipe Company’s Annual Report on Form 10-K for the year ended December 31, 2008,2016, and the effectiveness of theNorthwest Pipe Company’s internal control over financial reporting as of December 31, 20082016, have been audited by Deloitte & ToucheMoss Adams LLP, an independent registered public accounting firm, as stated in their reports, which arereport thereon, and incorporated herein by reference. Such consolidated financial statements financial statement schedule and retrospective adjustments have been soare incorporated herein by reference in reliance upon such report given on the reportsauthority of such firm given upon their authority as experts in auditingaccounting and accounting.auditing.

The financial statements as of December 31, 2015 and for each of the yeartwo years in the period ended December 31, 2006, before the effects of the adjustments to retrospectively apply the change to the reporting segment (not separately included or incorporated by reference in the Prospectus) have been audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm. The adjustments to those financial statements to retrospectively apply the change in the reporting segment described in Note 16 have been audited by Deloitte & Touche LLP, an independent registered public accounting firm. The consolidated financial statements for the year ended December 31, 20062015 incorporated in this prospectusProspectus by reference to the Annual Report on Form 10-K for the year ended December 31, 20082016 have been so incorporated in reliance on the reportsreport of (i) PricewaterhouseCoopers LLP, solely with respect to those financial statements before the effects of the adjustments to retrospectively apply the change in the reporting segment described in Note 16, and (ii) Deloitte & Touche LLP solely with respect to the adjustments to those financial statements to retrospectively apply the change in the reporting segment described in Note 16,an independent registered public accounting firm, given on the authority of such firmssaid firm as experts in auditing and accounting.

WHERE YOU CANFIND MORE INFORMATION

We file annual reports, quarterly reports, current reports, proxy statements and other information with the SEC. You may read and copy any of our SEC filings at the SEC’s Public Reference Room at 100 F Street N.E. Washington DC 20549. You may call the SEC at 1-800-SEC-0330 for further information about the Public Reference Room. Our SEC filings are also available to the public on the SEC’s web site athttp://www.sec.gov.

We make available, free of charge, on our website at http:www.nwpipe.com, our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports and statements as soon as reasonably practicable after they are filed with the SEC. The contents of our web site are not part of this prospectus, and the reference to our web site does not constitute incorporation by reference into this prospectus of the information contained at that site.

INFORMATION INCORPORATED BYREFERENCE

The SEC permits us to “incorporate by reference” the information and reports that we file with it. This means we can disclose important information to you by referring to another document. The information that we incorporate by reference is considered part of this prospectus, and later information that we file later with the SEC will automatically update and supersede this information. Any statement contained in any document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in or omitted from this prospectus or any accompanying prospectus supplement, or in any other subsequently filed document which also is or is deemed to be incorporated by reference herein, modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus. We incorporate by reference the documents listed below (other than, in each case, documents or information deemed to have been furnished and any future filings madenot filed in accordance with the SEC under Sections 13(a), 13(c), 14 or 15(d)rules):

All reports and the description of our common stock contained in our Registration Statement on Form 8-A filed on November 2, 1995 and our Registration Statement on Form 8-A filed on July 1, 1999.

Also incorporated by reference into this prospectus are allother documents that we maysubsequently file with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act prior to the termination of this offering, including all such reports and documents we may file with the SEC after the date of the initial registration statement and prior to effectiveness of the registration statement will also be incorporated by reference into this prospectus and afterdeemed to be part of this prospectus from the date of this prospectusfiling of such reports and before we stop offeringdocuments, provided that all documents and information “furnished” by the securities described in this prospectus. These documents include periodic reports, such as annual reports on Form 10-K, quarterly reports on Form 10-QCompany to the SEC and current reports on Form 8-K, as well as proxy statements. Pursuant to General Instruction B of Form 8-K, any information submitted under Item 2.02, Results of Operations and Financial Condition, or Item 7.01, Regulation FD Disclosure, of Form 8-K isnot “filed” are not deemed to be “filed” for the purpose of Section 18 of the Exchange Act, and we are not subjectincorporated by reference herein.

Any statement contained in any document incorporated by reference herein will automatically be deemed to be modified or superseded to the liabilities of Section 18 with respectextent that information in this prospectus or in a later filed document that is incorporated or deemed to information submitted under Item 2.02 or Item 7.01 of Form 8-K. We are not incorporatingbe incorporated herein by reference modifies or supersedes such statement. Information in future filings incorporated by reference in this prospectus updates and supplements the information provided in this prospectus. Any statements in any future filings will automatically be deemed to modify and supersede any information submitted under Item 2.02 or Item 7.01 of Form 8-K intoin any filing under the Securities Act or the Exchange Act or into this prospectus.

We have alsodocument we previously filed a registration statement on Form S-3 with the SEC of which this prospectus forms a part. This prospectus does not contain all ofthat is incorporated or deemed to be incorporated herein by reference to the information set forthextent that statements in the registration statement. You should read the registration statement for further information about us and about our securities.later filed document modify or replace such earlier statements.

We will furnish without charge to you, on

Upon written or oral request, we will furnish to you, without charge, a copy of any or all of these filings.documents that are incorporated by reference into this prospectus but not delivered with the prospectus, including exhibits which are specifically incorporated by reference into such documents. You should direct any requests for documents to Investor Relations, Northwest Pipe Company, 5721 SE Columbia Way, Suite 200, Vancouver, Washington 98661, telephone (360) 397-6250.

$125,000,000

Common Stock

Preferred Stock

Warrants

Debt Securities

PROSPECTUS

, 2009

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution.

The following table provides the various expenses payable by Northwest Pipe Company in connection with the issuance and distribution of the securities being registered, other than underwriting discounts and commissions. All amounts shown are estimates except the Securities and Exchange Commission registration fee.

__________

*To be provided by amendment.

Item 15. Indemnification of Directors and Officers.

As an Oregon corporation, the Company is subject to the Oregon Business Corporation Act (“OBCA”) and the exculpation from liability and indemnification provisions contained therein. Pursuant to Section 60.047(2)(d) of the OBCA, Article IV of the Company’s Second Restated Articles of Incorporation, as amended (the “Articles”), eliminates the liability of the Company’s directors to the Company or its shareholders, except for any liability related to breach of the duty of loyalty, actions not in good faith and certain other liabilities.

Section 60.387 et seq. of the OBCA allows corporations to indemnify their directors and officers against liability where the director or officer has acted in good faith and with a reasonable belief that actions taken were in the best interests of the corporation or at least not opposed to the corporation’s best interests and, if in a criminal proceeding, the individual had no reasonable cause to believe the conduct in question was unlawful. Under the OBCA, corporations may not indemnify against liability in connection with a claim by or in the right of the corporation but may indemnify against the reasonable expenses associated with such claims. Corporations may not indemnify against breaches of the duty of loyalty. The OBCA provides for mandatory indemnification of directors against all reasonable expenses incurred in the successful defense of any claim made or threatened whether or not such claim was by or in the right of the corporation. Finally, a court may order indemnification if it determines that the director or officer is fairly and reasonably entitled to indemnification in view of all the relevant circumstances whether or not the director or officer met the good faith and reasonable belief standards of conduct set out in the statute.

The OBCA also provides that the statutory indemnification provisions are not deemed exclusive of any other rights to which directors or officers may be entitled under a corporation’s articles of incorporation or bylaws, any agreement, general or specific action of the board of directors, vote of shareholders or otherwise.

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The Articles require the Company to indemnify its directors and officers to the fullest extent not prohibited by law.

Insofar as indemnification for

We hold an insurance policy covering directors and officers with respect to certain liabilities, including liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered hereunder, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.otherwise.

Item 16. Exhibits.

The following exhibits are filed as part of this registration statement:

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____________

* To be filed by amendment or as an exhibit to a report filed under the Exchange Act, and incorporated herein by reference, if applicable.

Item 17. Undertakings.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Vancouver, State of Washington, on April 16, 2009.March 17, 2017.

KNOW ALL BY THESE PRESENTS that each individual whose signature appears below hereby constitutes and appoints William R. TagmyerRichard A. Roman and Brian W. Dunham,Scott Montross, and each of them, his true and lawful attorneys-in-fact and agents with full power of substitution, for him and in his name, place and stead, in any and all capacities, to sign any and all pre- or post-effective amendments to this registration statement and any subsequent registration statement for the same offering which may be filed under Rule 462(b) under the Securities Act, (a “Rule 462(b) registration statement”) and any and all pre- or post-effective amendments thereto, and to file the same, with all exhibits thereto, and all documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing which they, or any of them, may deem necessary or advisable to be done in connection with this registration statement or any Rule 462(b) registration statement,therewith, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or any of them, or any substitute or substitutes for any or all of them, may lawfully do or cause to be done by virtue hereof.

Witness our hands on the date set forth below.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been duly signed by the following persons in the capacities indicated on April 16, 2009.March 17, 2017.

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