The common stock is listed on the New York Stock Exchange under the symbol “SRP.” The last reported sale price of our common stock on August 9, 2006 was $14.50 per share.

See “Risk Factors” on page S-3 of this prospectus supplement and in our Annual Report on Form 10-K for the year ended December 31, 2005 and our Quarterly Report on Form 10-Q for the quarter ended June 30, 2006, which are incorporated by reference herein, to learn about risks you should consider before investing in our common stock.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The underwriter has agreed to purchase the common stock from us at a price of $      per share which will result in $           of proceeds to us. The underwriter may also purchase up to an additional 3,000,000 shares at the same price per share within 30 days from the date of this prospectus supplement to cover over-allotments.

The underwriter may offer the common stock in transactions on the New York Stock Exchange, in the over-the-counter market or through negotiated transactions at market price or at negotiated prices.

The common stock is expected to be ready for delivery in book-entry form only through The Depository Trust Company on or about August   , 2006.

This document consists of two parts. The first part is this prospectus supplement, which describes the specific terms of this offering. The second part is the accompanying prospectus, which describes more general information, some of which may not apply to this offering. You should read both this prospectus supplement and the accompanying prospectus, together with additional information described in the accompanying prospectus under the headings “Where You Can Find More Information” and “Incorporation Of Information We File With The Securities And Exchange Commission.”

If the description of the offering varies between this prospectus supplement and the accompanying prospectus, you should rely on the information in this prospectus supplement.

Any statement made in this prospectus supplement or in a document incorporated or deemed to be incorporated by reference in this prospectus supplement will be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in this prospectus supplement or in any other subsequently filed document that is also incorporated or deemed to be incorporated by reference in this prospectus supplement modifies or supersedes that statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus

You should rely only on the information in this prospectus supplement, the accompanying prospectus, any free writing prospectus relating to this offering and the documents incorporated by reference into this prospectus supplement and accompanying prospectus. We have not authorized anyone to provide you with different information. You should not assume that the information in this prospectus supplement or the accompanying prospectus is accurate as of any date other than the date on the front of those documents. This prospectus supplement does not constitute an offer to sell or a solicitation of an offer to buy securities in any jurisdiction or to any person to whom it is unlawful to make such offer or solicitation in such jurisdiction.

No action is being taken in any jurisdiction outside the United States to permit a public offering of the shares of our common stock or possession or distribution of this prospectus supplement, the accompanying prospectus and the documents we have incorporated by reference in that jurisdiction. Persons who come into possession of this prospectus supplement and the accompanying prospectus in jurisdictions outside the United States are required to inform themselves about and to observe any restrictions as to this offering and the distribution of this prospectus supplement and the accompanying prospectus applicable to that jurisdiction.

In addition to the other information contained elsewhere or incorporated by reference in this prospectus supplement and the accompanying prospectus, you should carefully consider the “Risk Factors” sections in our 2005 Form 10-K as supplemented by our Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2006, as well as the following risk factors, before you decide to invest in our common stock.

We are a holding company with no significant operations of our own. Our cash flows are substantially derived from dividends paid to us by the Utilities, which are typically utilized to service our debt and pay dividends on our common stock, with the balance, if any, reinvested in our subsidiaries as contributions to capital. The Utilities are subject to restrictions on their ability to pay dividends to us under the terms of certain of their respective financing agreements. In addition, certain provisions of the Federal Power Act could, depending on the interpretation thereof, limit or prohibit the payment of dividends by the Utilities to us. Finally, the Public Utilities Commission of Nevada (“PUCN”) has issued an order to the effect that, until the senior secured debt of each of the Utilities obtains investment grade status from at least two rating agencies, the Utilities’ combined annual dividend payments to us are limited to our actual debt service requirements. See “Dividends From Subsidiaries” below.

It is impossible to know whether the market price of our common stock will rise or fall. Numerous factors influence the trading price of our common stock. These factors include changes in our financial condition, results of operations or future prospects. Additionally, complex and interrelated political, economic, financial and other factors can negatively affect the capital markets generally, the stock exchange on which our common stock is traded and the market segments of which we are a part.

Provisions in our restated and amended articles of incorporation and our by-laws may discourage, delay or prevent a merger or acquisition involving us that our stockholders may consider favorable.

In addition, we are also subject to the anti-takeover provisions of Nevada’s Control Share Acquisition Act (Nevada Revised Statutes 78.378-78.3793), which would prohibit an acquiror, under certain circumstances, from voting shares of our stock after crossing specific threshold ownership percentages, unless the acquiror obtains the approval of the our stockholders. The first such threshold is the acquisition of at least one-fifth but less than one-third of the outstanding voting power.

We are also subject to Nevada’s Combination with Interested Stockholders Statute (Nevada Revised Statutes 78.411-78.444) which prohibits an “interested stockholder” from entering into a “combination” with us unless certain conditions are met. An “interested stockholder” is a person who, together with affiliates and associates, beneficially owns (or within the prior three years, did beneficially own) 10% or more of the our voting stock.

Nevada law provides that no person may acquire direct or indirect control of an entity that holds a controlling interest in a public utility without the prior approval of the PUCN. Nevada law, however, permits the transfer of not more than 25 percent of the Common Stock of an entity that holds a controlling interest in a public utility without the prior approval of the PUCN. We hold a controlling interest in both NPC and SPPC, which are public utilities in Nevada. Accordingly, no person may acquire 25 percent or more of the Common Stock without first obtaining the approval of the PUCN. Any transaction that violates such restriction is not valid for any purpose.

Upon a change of control, the holders of the Utilities’ and our existing debt instruments and the lenders under the Utilities’ existing credit facilities may have the right to require us to redeem notes or

Since we are a holding company, substantially all of our cash flow is provided by dividends paid to us by NPC and SPPC on their common stock, all of which is owned by us. Since NPC and SPPC are public utilities, they are subject to regulation by state utility commissions, which may impose limits on investment returns or otherwise impact the amount of dividends that the Utilities may declare and pay, and to a federal statutory limitation on the payment of dividends. In addition, certain agreements entered into by the Utilities set restrictions on the amount of dividends they may declare and pay and restrict the circumstances under which such dividends may be declared and paid. The specific restrictions on dividends contained in agreements to which NPC and SPPC are a party, as well as specific regulatory limitations on dividends, are summarized below.

The following notes and credit agreement limit the amount of payments in respect of common stock that NPC may make to us:

However, the dividend payment limitation does not apply to payments by NPC to enable us to pay our reasonable fees and expenses, provided that:

The terms of the various series of notes and the Second Amended and Restated Revolving Credit Agreement also permit NPC to make payments to us in excess of the amounts payable discussed above in an aggregate amount not to exceed:

In addition, NPC may make payments to us in excess of the amounts described above so long as, at the time of payment and after giving effect to the payment:

Since NPC meets (i) and (ii) above, NPC would have been able to pay up to a maximum of $52 million to us as of June 30, 2006.

If NPC’s Series G Notes, Series I Notes, or Series L Notes are upgraded to investment grade by both Moody’s Investors Service, Inc. (“Moody’s”) and Standard & Poor’s Rating Group, Inc. (“S&P”), the dividend restrictions described above will be suspended and will no longer be in effect so long as the applicable series of notes remains investment grade. If NPC’s General and Refunding Mortgage Bonds, Series K, which serve as collateral under NPC’s Second Amended and Restated Credit Agreement (the “Series K Bonds”), are upgraded to investment grade by any two of Moody’s, S&P and Fitch Ratings (“Fitch”), the dividend restrictions in NPC’s Second Amended and Restated Credit Agreement, described above, will be suspended and will no longer be in effect so long as the Series K Bonds remain investment grade.

However, the dividend payment limitation does not apply to payments by SPPC to enable us to pay our reasonable fees and expenses provided that:

The terms of the Series H Notes also permit SPPC to make payments to us in excess of the amounts payable discussed above in an aggregate amount not to exceed $25 million from the date of the issuance of the Series H Notes. The terms of the Amended and Restated Revolving Credit Agreement also permit SPPC to make payments to us in excess of the amounts payable above in an aggregate amount not to exceed $50 million from the date of the establishment of the Amended and Restated Revolving Credit Agreement.

In addition, SPPC may make payments to us in excess of the amounts described above so long as, at the time of payment and after giving effect to the payment:

Since SPPC meets (i) and (ii) above, SPPC would be able to pay up to a maximum of $52 million to us as of June 30, 2006.

If SPPC’s Series H Notes are upgraded to investment grade by both Moody’s and S&P, the dividend restrictions described above will be suspended and will no longer be in effect so long as the Series H Notes remain investment grade. If SPPC’s General and Refunding Mortgage Bonds, Series L, which serve as collateral under SPPC’s Amended and Restated Credit Agreement (the “Series L Bonds”), are upgraded to investment grade by any two of Moody’s, S&P and Fitch, the dividend restrictions in SPPC’s Amended and Restated Credit Agreement, decribed above, will be suspended and will no longer be in effect so long as the Series L Bonds remain investment grade.

We estimate that we will receive net proceeds of this offering, without the exercise of the underwriter’s over-allotment option, of approximately $      million ($      million if the underwriter’s over-allotment option is exercised in full), after deducting estimated expenses payable by us. We intend to use the net proceeds to make a capital contribution to NPC of at least $200 million to be used to repay indebtedness. The remaining proceeds will be invested in short-term instruments pending their use, which may be for additional capital contributions to one or both Utilities, for the repayment of a portion of our indebtedness, and/or for general corporate purposes.

Our common stock is traded on the New York Stock Exchange under the symbol “SRP.” The following table sets forth the high and low reported sale prices per share of the common stock in the consolidated transaction reporting system in “The Dow Jones News Referral Service” for the stated quarters. For similar information for prior periods, please refer to the table under the caption “Market For Registrant’s Common Equity, Related Stockholder Matters And Issuer Purchases Of Equity Securities (SPR)” in our 2005 Form 10-K.

On August 9, 2006, the last reported sale price of the common stock was $14.50 per share.

The Board of Directors (the “Board”) last declared a dividend on our common stock on February 6, 2002. Since that time, the Board has determined not to pay a dividend on our common stock. Dividends are considered periodically by our Board and are subject to factors that ordinarily affect dividend policy, such as current and prospective earnings, current and prospective business conditions, regulatory factors, our financial conditions and other matters within the discretion of the Board, as well as dividend restrictions set forth in our 85/8% Senior Notes due 2014, 7.803% Senior Notes due 2012 and 6.75% Senior Notes due 2017 and dividend restrictions applicable to our subsidiaries. The Board will continue to review the factors described above on a periodic basis to determine if and when it would be prudent to declare a dividend on our common stock. There is no guarantee that dividends will be paid in the future, or that, if paid, the dividends will be paid at the same amount or with the same frequency as in the past. See “Dividends From Subsidiaries” above for information regarding restrictions on the Utilities’ ability to pay dividends to us, including a PUCN order which currently limits such dividends to amounts we require for our debt service obligations.

We and Deutsche Bank Securities Inc. have entered into an underwriting agreement with respect to the shares of common stock being offered and sold in this offering. Subject to certain conditions contained in an underwriting agreement, such as the receipt by the underwriter of officers’ certificates and legal opinions, the underwriter has agreed to purchase the number of shares indicated on the cover page of this prospectus supplement.

The underwriter may receive from purchasers of the shares normal brokerage commissions in amounts agreed with such purchasers.

The underwriter proposes to offer the shares of common stock from time to time for sale in one or more transactions in the NYSE, in the over-the-counter market, through negotiated transactions or otherwise at market prices prevailing at the time of sale, at prices related to prevailing market prices or at negotiated prices, subject to receipt and acceptance by it and subject to its right to reject any order in whole or in part. In connection with the sale of the shares of common stock offered hereby, the underwriter may be deemed to have received compensation in the form of underwriting discounts. The underwriter may effect such transactions by selling shares of common stock to or through dealers, and such dealers may receive compensation in the form of discounts, concessions or commissions from the underwriter and/or purchasers of shares of common stock for whom they may act as agents or to whom they may sell as principal.

In connection with the offering, the underwriter may purchase and sell shares of common stock in the open market. These transactions may include short sales and purchases to cover positions created by short sales. Short sales involve the sale by the underwriter of a greater number of shares than it is required to purchase in the offering. The underwriter will need to close out any short sale by purchasing shares in the open market. The underwriter is likely to create a short position if it is concerned that there may be downward pressure on the price of the common stock in the open market after pricing that could adversely affect investors who purchase in the offering.

Purchases to cover a short position, as well as other purchases by the underwriter for its own account, may have the effect of preventing or retarding a decline in the market price of the company’s stock, and may maintain or otherwise affect the market price of the common stock. As a result, the price of the common stock may be higher than the price that otherwise might exist in the open market. If these activities are commenced, they may be discontinued at any time. These transactions may be effected on NYSE, in the over-the-counter market or otherwise.

We have granted an option to the underwriter to purchase up to an aggregate of 3,000,000 additional shares of our common stock. The underwriter may exercise this option for 30 days from the date of this prospectus supplement solely to cover any over-allotments.

The Company has agreed with the underwriter, subject to certain exceptions, not to offer, sell or otherwise dispose of or hedge its common stock or securities convertible into or exchangeable for shares of common stock during the period from the date of this prospectus supplement continuing through the date 90 days after the date of this prospectus supplement (subject to extension in certain circumstances), except with the prior written consent of the underwriter.

The Company’s officers have agreed with the underwriter not to dispose of or hedge any of their common stock or securities convertible into or exchangeable for shares of common stock during the period from the date of this prospectus supplement continuing through the date 60 days after the date of this prospectus supplement (subject to extension in certain circumstances), except with the prior written consent of the underwriter.

We estimate that our share of the total expenses of this offering will be approximately $200,000.

The Company has agreed to indemnify the underwriter against certain liabilities, including liabilities under the Securities Act of 1933.

Because more than 10% of the net offering proceeds may be paid to affiliates of NASD members participating in the distribution of this offering, this offering may be made pursuant to Rule 2710(h) of the NASD Conduct Rules.

The underwriter and its affiliates have provided investment banking, commercial banking and financial advisory services for us and our subsidiaries, Nevada Power Company and Sierra Pacific Power Company, from time to time for which they have received customary fees and reimbursements of expenses and may in the future provided additional services.

Certain legal matters will be passed upon for us by Choate, Hall & Stewart LLP, Boston, Massachusetts. Matters of Nevada law will be passed upon by Woodburn and Wedge, Reno, Nevada. Certain legal matters in connection with the offered securities will be passed upon for the underwriter by Dewey Ballantine LLP, New York, New York.

Sierra Pacific Resources is a Nevada corporation.

Sierra Pacific Resources may offer shares of common stock and debt securities from time to time. We will provide specific terms of any offering in supplements to this prospectus. You should read this prospectus and the prospectus supplement carefully before you invest.

Additional information on our plan of distribution can be found inside under “Plan of Distribution.” We will further describe the plan of distribution for any securities offered hereunder in the applicable prospectus supplement.

The common stock of Sierra Pacific Resources is listed on the New York Stock Exchange under the symbol “SRP.”

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission utilizing a shelf registration process. Under this shelf process, we may offer the common stock and debt securities described in this prospectus in one or more offerings. In this prospectus, we refer to the common stock and debt securities collectively as the “securities.” This prospectus provides you with a general description of the securities we may offer. Each time we offer securities, we will provide you with a prospectus supplement and, if applicable, a pricing supplement. The prospectus supplement and any applicable pricing supplement will describe the specific amounts, prices and terms of the debt securities being offered and, in the case of the common stock, will describe the offering price of the common stock. The prospectus supplement and any applicable pricing supplement may also add to, update or change the information in this prospectus. It is important for you to read and consider all information contained or incorporated by reference in this prospectus, the applicable prospectus supplement and any applicable pricing supplement. You should also read and consider the information in the documents to which we have referred you in “Where You Can Find More Information” in this prospectus.

No person is authorized to give any information or to make any representations other than those contained or incorporated by reference in this prospectus and, if given or made, such information or representations must not be relied upon as having been authorized. This prospectus does not constitute an offer to sell or the solicitation of an offer to buy any securities other than the securities described in this prospectus or an offer to sell or the solicitation of an offer to buy such securities in any circumstances in which such offer or solicitation is unlawful. Neither the delivery of this prospectus, the applicable prospectus supplement or any applicable pricing supplement, nor any sale made hereunder, shall under any circumstances create any implication that there has been no change in our affairs since the date of this prospectus, or that the information contained or incorporated by reference in this prospectus is correct as of any time subsequent to the date of such information.

The distribution of this prospectus, the applicable prospectus supplement and any applicable pricing supplement and the offering of the securities in certain jurisdictions may be restricted by law. This prospectus does not constitute an offer, or any invitation on our behalf, to subscribe to or purchase any of the securities, and may not be used for or in connection with an offer or solicitation by anyone, in any jurisdiction in which such an offer or solicitation is not authorized or to any person to whom it is unlawful to make such an offer or solicitation.

Investing in our securities involves risks. You are urged to read and carefully consider the information under the heading “Risk Factors” in:

Before making an investment decision, you should carefully consider these risks as well as other information we incorporate by reference in this prospectus. The risks and uncertainties that we have described are not the only ones facing us or Nevada Power Company (“NPC”) or Sierra Pacific Power Company (“SPPC” and, together with NPC, the “Utilities”). The prospectus supplement applicable to each type or series of securities we offer under this registration statement will contain additional information about risks applicable to an investment our company and the particular type of securities we are offering under that prospectus supplement.

Certain statements included or incorporated by reference in this prospectus are “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933 (the “Securities Act”) and Section 21E of the Securities Exchange Act of 1934 (the “Exchange Act”), which represent our expectations or beliefs concerning future events. When used in this prospectus, the words “expects,” “plans,” “anticipates,” and similar expressions are intended to identify forward-looking statements. All forward-looking statements contained or incorporated by reference in this prospectus are based upon information available to us on the date of this prospectus. We undertake no obligation to update publicly or revise any forward-looking statement, whether as a result of new information, future events or otherwise. Forward-looking statements involve risks and uncertainties that could cause actual results to differ materially from historical experience or our expectations. In addition to the specific factors discussed in the “Risk Factors” section of this prospectus and our reports that are incorporated by reference, the following are factors that could cause our actual results or those of the Utilities to differ materially from those contemplated in any forward-looking statement:

Additional information concerning these and other factors is contained in our Securities and Exchange Commission filings, including but not limited to our Forms 10-K, 10-Q and 8-K, which are incorporated by reference into this prospectus and which we urge you to read.

We are subject to the informational requirements of the Exchange Act and file reports and other information with the Securities and Exchange Commission. Such reports, proxy statements and other information filed by us with the Securities and Exchange Commission can be inspected and copied at the public reference facilities maintained by the Securities and Exchange Commission at the Securities and Exchange Commission’s Public Reference Room at 100 F Street, N.E., Room 1580, Washington, D.C. 20549.

Information on the public reference rooms and their copy charges may be obtained from the Securities and Exchange Commission by calling 1-800-SEC-0330. The Securities and Exchange Commission also maintains an Internet site (http://www.sec.gov) that contains reports, proxy and information statements and other information regarding registrants, including us, that have been filed electronically with the Securities and Exchange Commission. Our common stock is listed and traded on the New York Stock Exchange (the “NYSE”). You may also inspect the information we file with the Securities and Exchange Commission at the NYSE’s offices at 20 Broad Street, New York, New York 10005. Information about us, including our Securities and Exchange Commission filings, is also available on our website at www.sierrapacificresources.com. The contents of our website are not incorporated into this prospectus or any accompanying prospectus supplement.

We have filed a registration statement on Form S-3 with the Securities and Exchange Commission covering the securities. This prospectus is part of that registration statement. As allowed by the Securities and Exchange Commission’s rules, this prospectus does not contain all of the information you can find in the registration statement and the exhibits to the registration statement. Because the prospectus may not contain all the information that you may find important, you should review the full text of these documents.

The Securities and Exchange Commission allows us to “incorporate by reference” in this prospectus the information in other documents that we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be a part of this prospectus, and information in documents that we file later with the Securities and Exchange Commission will automatically update and supersede information contained in documents filed earlier with the Securities and Exchange Commission or contained in this prospectus. We incorporate by reference in this prospectus the documents listed below and any future filings that we may make with the Securities and Exchange Commission under Sections 13(a), 13(c), 14, or 15(d) of the Exchange Act, prior to the termination of the offering under this prospectus; provided, however, that we are not incorporating, in each case, any documents or information deemed to have been “furnished” and not “filed” in accordance with Securities and Exchange Commission rules:

You may request a copy of any filings referred to above (excluding certain exhibits to the documents), at no cost, by writing or telephoning us at the following address:

We engage primarily in the power and energy businesses through several regulated subsidiaries. We completed a merger with NPC in July 1999, combining the two largest regulated electric utility companies in the state of Nevada. As of the date of this prospectus, we serve approximately 95% of Nevada residents, providing electricity and/or gas to approximately 1.1 million customers in service territories that cover northern and southern Nevada and the Lake Tahoe region of California. In addition to NPC and SPPC, we also operate several non-regulated businesses.

Nevada Power Company, our wholly owned subsidiary, is a public utility engaged in the distribution, transmission, generation and sale of electric energy to approximately 774,000 customers in southern Nevada. NPC has a total generating capacity of 3,066 MW from 27 gas, oil and coal generating units in its generating plants and serves customers in the communities of Las Vegas, North Las Vegas, Henderson, Searchlight, Laughlin and adjoining areas, including Nellis Air Force Base and the Department of Energy’s Nevada Test Site in Nye County.

Sierra Pacific Power Company, our wholly owned subsidiary is a public utility primarily engaged in the distribution, transmission, generation and sale of electric energy and natural gas in Nevada. SPPC has a total generating capacity of 1,045 MW of coal and natural gas/oil fired generating plants and provides electricity to approximately 353,000 customers in a 50,000 square mile service area in western, central and northeastern

Tuscarora Gas Pipeline Company is a joint venture partner with TransCanada Pipelines Ltd. in the operation of a 229 mile natural gas pipeline regulated by the Federal Energy Regulatory Commission (“FERC”) that serves Reno, northern Nevada and northeastern California.

We also operate non-utility businesses which, collectively, do not comprise a material amount of our total revenues or total assets.

We are incorporated in Nevada. Our principal executive offices are located at 6100 Neil Road, Reno, Nevada 89520 and our telephone number is 775-834-3600.

In this prospectus, “Sierra Pacific,” the “Company,” “we,” “us,” and “our” refer specifically to Sierra Pacific Resources, the holding company.

Since we are a holding company, substantially all of our cash flow is provided by dividends paid to us by NPC and SPPC on their common stock, all of which is owned by us. Since NPC and SPPC are public utilities, they are subject to regulation by state utility commissions, which may impose limits on investment returns or otherwise impact the amount of dividends that the Utilities may declare and pay, and to a federal statutory limitation on the payment of dividends. In addition, certain agreements entered into by the Utilities set restrictions on the amount of dividends they may declare and pay and restrict the circumstances under which such dividends may be declared and paid. The specific restrictions on dividends contained in agreements to which NPC and SPPC are party, as well as specific regulatory limitations on dividends, can be found in our Forms 10-K, 10-Q and 8-K, which are incorporated by reference into this prospectus. The prospectus supplement applicable to each offering of securities under this registration statement will contain additional information regarding dividend restrictions applicable to NPC and SPPC.

We intend to use the proceeds from the issuance of these securities to refinance, discharge and/or refund our existing indebtedness, to make capital contributions to our subsidiaries, and for general corporate purposes.

The specific allocations of the proceeds we receive from the sale of our securities will be described in the applicable prospectus supplement.

The authorized capital stock of Sierra Pacific Resources consists of 350,000,000 shares of Common Stock, $1.00 par value per share. The Company’s Common Stock is listed on the NYSE under the trading symbol “SRP.” The following description of the Common Stock summarizes provisions of, and is qualified in its entirety by reference to, the Company’s Articles of Incorporation and the laws of the State of Nevada.

All shares of Common Stock participate equally with respect to dividends and rank equally upon liquidation. Each share of Common Stock is entitled to one vote per share at all meetings of stockholders. The Common Stock has no preemptive rights and does not have cumulative voting rights.

The Board is classified, consisting of three classes of equal (or nearly equal) membership serving staggered three-year terms. The vote of the holders of two-thirds of the issued and outstanding shares of Common Stock is required to remove a director or directors from office or to amend the provisions of the Articles of Incorporation relating to election and removal of directors, unless, in the case of such an

The vote of the holders of two-thirds of the issued and outstanding shares of Common Stock, in addition to any class vote required by law, is required to effect certain mergers, sales of assets or stock issuances involving the Company and any holder of more than 10 percent of the Common Stock, unless certain “fair price” criteria and procedural requirements are satisfied or the transaction is approved by a majority of the directors (excluding any director affiliated with such 10 percent stockholder). The vote of the holders of two-thirds of the issued and outstanding shares of Common Stock is required to amend these “fair price” provisions.

Except as described above, the Company may amend its Articles of Incorporation upon the affirmative vote of the holders of a majority of the issued and outstanding shares of Common Stock.

In the event of any liquidation, dissolution or winding-up of the Company, the holders of Common Stock are entitled to receive pro rata the assets and funds of the Company remaining after satisfaction of all of its creditors.

The Company’s transfer agent and registrar is Wells Fargo Shareowner Services.

Nevada law provides that no person may acquire direct or indirect control of an entity that holds a controlling interest in a public utility without the prior approval of the PUCN. Nevada law, however, permits the transfer of not more than 25 percent of the Common Stock of an entity that holds a controlling interest in a public utility without the prior approval of the PUCN. The Company holds a controlling interest in both NPC and SPPC, which are public utilities in Nevada. Accordingly, no person may acquire more than 25 percent of the Common Stock without first obtaining the approval of the PUCN. Any transaction that violates such restriction is not valid for any purpose.

The Company is subject to Nevada’s Control Share Acquisition Act (Nevada Revised Statutes 78.378-78.3793), which prohibits an acquiror, under certain circumstances, from voting shares of a corporation’s stock after crossing specific threshold ownership percentages, unless the acquiror obtains the approval of the issuing corporation’s stockholders. The first such threshold is the acquisition of at least one-fifth but less than one-third of the outstanding voting power.

The Company is also subject to Nevada’s Combination with Interested Stockholders Statute (Nevada Revised Statutes 78.411-78.444) which prohibits an “interested stockholder” from entering into a “combination” with the Company, unless certain conditions are met. An “interested stockholder” is a person who, together with affiliates and associates, beneficially owns (or within the prior three years, did beneficially own) 10 percent or more of the Company’s voting stock.

From time to time we may issue debt securities in one or more series of senior debt securities (“debt securities”). Below is a description of the general terms of the debt securities. The particular terms of a series of debt securities will be described in a prospectus supplement.

Debt securities will be issued under an indenture, as supplemented from time to time (the “indenture”), between us and The Bank of New York, as trustee (the “indenture trustee”). The indenture will be subject to and governed by the Trust Indenture Act of 1939. The Bank of New York also acts as trustee under the general and refunding mortgage indentures of SPPC and NPC.

The indenture does not limit the amount of debt securities that we may issue, nor does it limit us or our subsidiaries from issuing any other unsecured debt. The debt securities will rank equally with all of our

Terms of the Debt Securities

Each prospectus supplement relating to an offering of a series of debt securities will describe the terms of such debt securities, including:

Prospective purchasers of debt securities should be aware that special U.S. Federal income tax, accounting and other considerations may be applicable to instruments such as the debt securities. The prospectus supplement relating to an issue of debt securities will describe these considerations, if applicable.

The provisions of the indenture permit us, without the consent of holders of any debt securities, to issue additional debt securities with terms different from those of debt securities previously issued and to reopen a previous series of debt securities and issue additional debt securities of that series.

We will pay or deliver principal and any premium, Additional Amounts, and interest in the manner, at the places and subject to the restrictions described in the indenture, the debt securities and the applicable prospectus supplement.

The indenture permits us to merge or consolidate, sell, lease, for a term extending beyond the last stated maturity of debt securities outstanding under the indenture, or convey, transfer or otherwise dispose of all or substantially all of our assets, if the following conditions are satisfied:

The indenture does not prevent or restrict any of the following:

The term “restricted subsidiary” is defined in the indenture as any of our operating subsidiaries that account for 10% or more of our consolidated revenues and/or assets.

The indenture may be modified or amended by us and the trustee, without notice to or the consent of any holders, with respect to certain matters contained in the indenture including:

In addition, under the indenture, we and the trustee may change the rights of holders of a series of debt securities with the written consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each affected series. However, the following changes may be made only with the consent of each holder of any outstanding debt securities affected:

The holders of at least a majority in principal amount of the outstanding debt securities of any series may, with respect to that series, waive past defaults under the indenture and waive our compliance with the provisions of the indenture, except as described under “— Events of Default” below.

Each of the following will be an Event of Default with respect to each series of debt securities issued under the indenture:

If an Event of Default with respect to debt securities of any series occurs and is continuing, the trustee or the holders of at least 25% in principal amount of the outstanding debt securities of that series may declare the entire principal amount of all debt securities of such series and the accrued interest thereon due and payable immediately (except, if the Event of Default (i) described in the fourth bullet is with respect to all series of securities then outstanding or (ii) described in the fifth or sixth bullets, occurs and is continuing, then the trustee or holders of at least 25% in principal of all the securities then outstanding under the indenture (treated as one class), may declare the entire principal amount of all debt securities then outstanding under the indenture and accrued interest thereon to be due and payable immediately). Holders of a majority in principal amount of the outstanding debt securities of an affected series may rescind and annul a declaration of acceleration if we deposit with the trustee enough money to cover overdue amounts on the outstanding debt securities other than the amounts that would be due as a result of the acceleration.

Holders of a majority in principal amount of the outstanding debt securities of an affected series may waive any past default or event of default of that series (except with respect to an Event of Default (i) described in the fourth bullet is with respect to all series of securities then outstanding or (ii) described in the fifth or sixth bullets, in which case a majority in principal amount of the securities then outstanding (voting as one class) is required to waive), except defaults or events of default regarding covenants that cannot be modified or amended without the consent of each holder of any outstanding debt securities affected (see “— Modification of Indenture; Waiver” above).

Holders of debt securities may not enforce the indenture or the relevant debt securities except as set forth in the indenture. The trustee under the indenture may refuse to enforce the indenture on the applicable debt securities unless it receives indemnification satisfactory to it. Subject to limitations contained in the indenture, holders of a majority in principal amount of debt securities issued under the indenture may direct the trustee in its exercise of any power granted to it under the indenture.

Notwithstanding any other provision in the indenture (including remedies which are subject to conditions precedent), each holder of debt securities will have the right, which is absolute and unconditional, to receive payment of the principal of and premium, if any, and interest, if any, on the holder’s debt securities, when due and to institute suit for the enforcement of payment. Such rights may not be impaired or affected without the consent of such holder.

We will not, nor will we permit any “restricted subsidiary” to, create, issue, assume, guarantee or permit to exist any indebtedness for borrowed money secured by a mortgage, security interest, pledge, lien or other encumbrance upon any shares of stock of any restricted subsidiary without effectively providing that the debt securities shall be secured equally and ratably with the indebtedness.

We will not, nor will we permit any restricted subsidiary to, issue, sell, assign, transfer or otherwise dispose of, directly or indirectly, any “capital stock” (other than nonvoting preferred stock) of any restricted subsidiary, except for:

The term “capital stock” is defined in the indenture as any and all shares, interests, rights to purchase, warrants, options, participations or other equivalents of or interests in corporate stock.

The indenture provides us with the option to discharge us from (a) all obligations of the debt securities of a series (except for administrative obligations) or (b) compliance with the covenants of the indenture with respect to such series. To exercise either option we must irrevocably deposit in trust with the indenture trustee money or obligations of, or guaranteed by, the United States sufficient to pay all of the principal of (including any mandatory redemption payments), premium, Additional Amounts and interest on the debt securities on the dates the payments are due. To exercise either option, we are required to deliver to the indenture trustee an opinion of tax counsel that the deposit and related defeasance would not cause the holders of the debt securities to recognize income, gain or loss for Federal income tax purposes. To exercise the option described in clause (a) above, the tax opinion must be based on a ruling of the Internal Revenue Service.

Each series of debt securities will be issued in fully registered form without coupons or in bearer form with or without coupons. Unless the applicable prospectus supplement provides otherwise, registered debt securities will be issued in denominations of $1,000 or integral multiples thereof and debt securities issued in bearer form will be issued in the denomination of $5,000. The indenture provides that debt securities may be issued in global form. If any series of debt securities is issuable in global form, the applicable prospectus supplement will describe the circumstances, if any, under which beneficial owners of interests in any of those global debt securities may exchange their interests for debt securities of that series and of like tenor and principal amount in any authorized form and denomination.

Holders may present debt securities for exchange, and registered debt securities for transfer, in the manner, at the places and subject to the restrictions set forth in the indenture, the debt securities and the applicable prospectus supplement. Holders may transfer debt securities in bearer form and the coupons, if any, appertaining to the debt securities will be transferable by delivery. There will be no service charge for any registration of transfer of registered debt securities or exchange of debt securities, but we may require payment of a sum sufficient to cover any tax or other governmental charges that may be imposed in connection with any registration of transfer or exchange. Bearer securities will not be issued in exchange for registered securities.

In the event of any redemption of debt securities of any series, we will not be required to:

The debt securities of each series may be issued in whole or in part in global form. A debt security in global form will be deposited with, or on behalf of, a depositary, which will be named in an applicable prospectus supplement. A global security may be issued in either registered or bearer form and in either temporary or definitive form. A global debt security may not be transferred, except as a whole, among the depositary for such debt security and/or its nominees and/or successors. If any debt securities of a series are issuable as global securities, the applicable prospectus supplement will describe any circumstances when beneficial owners of interests in any global security may exchange those interests for definitive debt securities

Unless otherwise indicated in the applicable prospectus supplement, payment of the interest on any debt securities (other than bearer securities) on any interest payment date will be made to the person in whose name the debt securities are registered.

Unless otherwise indicated in the applicable prospectus supplement, principal of and any premium, Additional Amounts and interest on the debt securities (other than bearer securities) of a particular series will be payable at the office of the paying agents designated by us. Unless otherwise indicated in the prospectus supplement, the principal corporate trust office of the trustee in The City of New York will be designated as sole paying agent for payments with respect to debt securities of each series.

All moneys paid by us to a paying agent or the trustee for the payment of the principal, premium additional amounts or interest on a debt security which remains unclaimed at the end of one year will be repaid to us, and the holder of the debt security thereafter may look only to us for payment thereof.

The indenture and debt securities will be governed by and construed under the laws of the State of New York, without regard to conflicts of laws principles thereof.

We may sell the securities (a) through agents; (b) through underwriters or dealers; (c) directly to one or more purchasers; or (d) through a combination of any of these methods of sale. We will identify the specific plan of distribution, including any underwriters, dealers, agents or direct purchasers and their compensation in a prospectus supplement.

Unless otherwise indicated in the applicable prospectus supplement, certain legal matters will be passed upon for us by Choate, Hall & Stewart LLP, Boston, Massachusetts. Matters of Nevada law will be passed upon by Woodburn and Wedge, Reno, Nevada. Unless otherwise indicated in the applicable prospectus supplement, legal matters in connection with the offered securities will be passed upon for the underwriter(s), dealer(s) or agent(s) by Dewey Ballantine LLP, New York, New York.

The consolidated financial statements, the related financial statement schedule and management’s report on the effectiveness of internal control over financial reporting, incorporated in this prospectus by reference from our Annual Report on Form 10-K for the year ended December 31, 2005, have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their reports which are incorporated herein by reference, and have been so incorporated in reliance upon the reports of such firm given upon their authority as experts in accounting and auditing.