Exhibit 99.1


                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


         In connection with the Quarterly Report of Sierra Pacific Resources,
Nevada Power Company, and Sierra Pacific Power Company (the "Companies") on Form
10-Q for the period ending June 30, 2002 as filed with the Securities and
Exchange Commission on the date hereof (the "Report"), I, Walter M. Higgins,
III, Chief Executive Officer of the Companies, certify, pursuant to 18 U.S.C.
Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of
2002, that:

         (1)      the Report fully complies with the requirements of section
13(a) or 15(d) of the Securities Exchange Act of 1934; and

         (2)      the information contained in the Report fairly presents, in
all material respects, the financial condition and results of operations of the
Companies.




/s/ Walter M. Higgins, III
- ---------------------------------
Walter M. Higgins, III
Chief Executive Officer
August 14, 2002






This Certification accompanies this Report pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002 and shall not, except to the extent required by the
Sarbanes-Oxley Act of 2002, be deemed filed by the Companies for purposes of
Section 18 of the Securities Exchange Act of 1934, as amended.