Exhibit 5.1

                                [CH&S Letterhead]

                                                   May 6, 2003

Sierra Pacific Resources
P.O. Box 30150
6100 Neil Road
Reno, Nevada 89520

              Re:    Sierra Pacific Resources

Ladies and Gentlemen:

         This opinion is delivered in connection with a registration statement
on Form S-3, File No. 333-__________, as amended (the "Registration Statement"),
of Sierra Pacific Resources, a Nevada corporation, (the "Company") relating to
the registration of $300,000,000 aggregate principal amount of the Company's
7-1/4% Convertible Notes due 2010 (the "Notes") issued under the Indenture,
dated February 14, 2003, between Sierra Pacific Resources and The Bank of New
York, as Trustee (the "Indenture"), shares of common stock issuable upon
conversion of the Notes (the "Common Stock") and common stock purchase rights
(the "Rights") related thereto.

         In connection with rendering this opinion, we have examined such
corporate records, certificates and other documents as we have considered
necessary for the purposes of this opinion. In such examination, we have assumed
the genuineness of all signatures, the authenticity of all documents submitted
to us as originals, the conformity to the original documents of all documents
submitted to us as copies and the authenticity of the originals of such latter
documents. As to any facts material to our opinion, we have, when relevant facts
were not independently established, relied upon the aforesaid records,
certificates and documents.

         As counsel for the Company, we advise you as follows:

         1.    The Company is a corporation duly organized and legally existing
under the laws of the State of Nevada.

         2.    When the following steps shall have been taken, the Notes will be
valid, legal and binding obligations of the Company (except as the enforcement
thereof may be limited by bankruptcy, insolvency, reorganization, moratorium
(including, without limitation, all laws relating to fraudulent transfers), or
other similar laws relating to or affecting enforcement of creditors' rights and
remedies generally, or by general principles of equity (regardless of whether
enforcement is considered in a proceeding in equity or at law)):

         (a)      Compliance with the Securities Act and the Trust Indenture Act
                  of 1939, as amended, and action of the Securities and Exchange
                  Commission permitting the Registration Statement to become
                  effective;

         (b)      Execution and filing with the Trustee of the proper papers
                  with respect to the Notes; and




         (c)      Issuance and delivery of the Notes in accordance with the
                  corporate authorizations and in accordance with the terms and
                  provisions of the Indenture.

         3.    When the following steps shall have been taken, the Common Stock
and the Rights will be validly issued, fully paid and non-assessable:

         (a)      Compliance with the Securities Act of 1933, as amended, and
                  action of the Securities and Exchange Commission permitting
                  the Registration Statement to become effective; and

         (b)      The issuance of the Common Stock and the Rights in conformity
                  with the Registration Statement and the Indenture.

         The opinion set forth above is subject to the limitation contained in
the Company's Restated Articles of Incorporation, as amended to date, as to the
total number of authorized shares available for issuance.

         We are of the opinion that the information contained in the
Registration Statement under the caption "Certain United States Federal Income
Tax Consequences" constitutes an accurate description, in general terms, of the
indicated federal income tax consequences to a holder of the Notes, with respect
to the purchase, ownership and disposition of the Notes, the Common Stock or the
Rights acquired upon conversion of a Note as contemplated in the Registration
Statement.

         Insofar as this opinion relates to matters of law and legal conclusions
governed by the laws of the State of Nevada, we base it on the opinion of
Messrs. Woodburn and Wedge of Reno, Nevada, as evidenced by the opinion of such
firm to be filed with the Registration Statement and the consent contained in
such opinion to the statements made in the Registration Statement in regard to
such firm. Our opinions as to such matters are based on the assumptions and
subject to the qualifications and limitations set forth in such opinion letter.

         We hereby consent to be named in the Registration Statement and in any
amendments thereto as counsel for the Company, to the statements with reference
to our firm made in the Registration Statement, and to the filing and use of
this opinion as an exhibit to the Registration Statement.

                                                  Very truly yours,



                                                  /s/ Choate, Hall & Stewart
                                                  -----------------------------
                                                  CHOATE, HALL & STEWART