Exhibit 5.1


                       [Choate, Hall & Stewart Letterhead]




                                                              August 22, 2001



Sierra Pacific Power Company
P.O. Box 10100
6100 Neil Road
Reno, Nevada 89520

Ladies and Gentlemen:

         This opinion is delivered in connection with the filing of a
registration statement on Form S-4, File No. 333-_____ (the "Registration
Statement") under the Securities Act of 1933, as amended (the "Securities Act"),
relating to the registration of $320,000,000 aggregate principal amount of the
Company's 8% General and Refunding Mortgage Bonds, Series A, due June 1, 2008
(the "New Bonds"), in connection with an offer by the Company to issue the New
Bonds in exchange for the Company's 8% General and Refunding Mortgage Bonds,
Series A, due June 1, 2008, that are currently outstanding in the same aggregate
principal amount (the "Old Bonds"), as described in the Registration Statement.
The New Bonds are to be issued pursuant to a General and Refunding Mortgage
Indenture dated as of May 1, 2001 (the "Indenture"), between the Company and The
Bank of New York, as Trustee (the "Trustee"), as supplemented by a First
Supplemental Indenture dated as of May 1, 2001 (the "Supplemental Indenture")
between the Company and the Trustee.

         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:

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





Sierra Pacific
August 22, 2001
Page 2



         When the following steps shall have been taken, the New Bonds will be
valid, legal and binding obligations of the Company:

         (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 New Bonds; and

         (c)      Issuance and delivery of the New Bonds in accordance with the
                  corporate authorizations and in accordance with the terms and
                  provisions of the Indenture (including the Supplemental
                  Indenture).

         We are of the opinion that the information contained in the
Registration Statement under the caption "Certain United States Federal Income
Tax Considerations" constitutes an accurate description, in general terms, of
the indicated federal income tax consequences to holders of the New Bonds upon
their exchange of the Old Bonds for the New Bonds 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.

         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