Analysts: Britta Carlson (702) 367-5624
Media: Karl Walquist (775) 834-3891

Sierra Pacific Resources (NYSE: SRP) announced today that its two regulated utility subsidiaries, Nevada Power Company and Sierra Pacific Power Company, have successfully amended their existing revolving credit facilities. The amended credit facilities total $750 million and have terms of 5 years. These amended facilities replace existing Nevada Power and Sierra Pacific Power committed credit facilities totaling $400 million, comprised of 3-year revolvers scheduled to mature in October 2007.

The amended credit facilities consist of a $500 million, 5-year revolving credit line for Nevada Power and a $250 million, 5-year revolving facility for Sierra Pacific Power. These facilities will continue to be used for general corporate purposes, including working capital needs, and, in the case of Nevada Power, may be utilized temporarily for the bridge financing of its pending acquisition of a 75% ownership interest in the Silverhawk Power Station in southern Nevada which still requires approval from the Federal Energy Regulatory Commission and Hart-Scott-Rodino clearance from the Federal Trade Commission. The amended credit facilities include sublimits for the issuance of standby letters of credit in the amounts of $375 million and $187.5 million for Nevada Power and Sierra Pacific Power, respectively.

Wachovia Securities, Union Bank of California, N.A. and Citigroup Global Markets Inc. acted as joint book managers for the Nevada Power credit facility. Wachovia Securities and Deutsche Bank Securities Inc. acted as joint book managers for the Sierra Pacific Power credit facility. A total of 20 banks comprise the new syndicated bank group for the amended credit facilities.

About Sierra Pacific Resources

Headquartered in Nevada, Sierra Pacific Resources is a holding company whose principal subsidiaries are Nevada Power Company, the electric utility for most of southern Nevada, and Sierra Pacific Power Company, the electric utility for most of northern Nevada and the Lake Tahoe area of California. Sierra Pacific Power Company also distributes natural gas in the Reno-Sparks area of northern Nevada. Other subsidiaries include the Tuscarora Gas Pipeline Company, which owns a 50 % interest in an interstate natural gas transmission partnership.

Forward-Looking Statements: This press release contains forward-looking statements regarding the future performance of Sierra Pacific Resources and its subsidiaries, Nevada Power Company and Sierra Pacific Power Company, within the meaning of the Private Securities Litigation Reform Act of 1995. These statements are subject to a variety of risks and uncertainties that could cause actual results to differ materially from current expectations. For Sierra Pacific Resources, these risks and uncertainties include, but are not limited to, Resources'ability to maintain access to the capital markets, Resources'ability to receive dividends from its subsidiaries and the financial performance of the Company's subsidiaries, particularly Nevada Power Company and Sierra Pacific Power Company. For Nevada Power Company and Sierra Pacific Power Company, these risks and uncertainties include, but are not limited to, their ability to purchase sufficient power to meet their power demands, unfavorable rulings in their rate cases, adverse decisions in the Enron litigation or other pending or future litigation, their ability to maintain access to the capital markets, and unseasonable weather conditions. Additional cautionary statements regarding other risk factors that could have an effect on the future performance of Sierra Pacific Resources, Nevada Power Company and Sierra Pacific Power Company are contained in their Quarterly Reports on Form 10-Q for the quarter ended September 30, 2005, and their Annual Reports on Form 10-K for the year ended December 31, 2004, filed with the SEC. The Companies undertake no obligation to release publicly the result of any revisions to these forward-looking statements that may be made to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events.