On December 26, 2002, at approximately 0945 mountain standard time, a Piper PA-28-181, N75337, was substantially damaged when it nosed over during a forced landing in an open field near Spanish Fork, Utah. The instrument rated private pilot was seriously injured, and his passenger received minor injuries. Keystone Aviation, Salt Lake City, Utah, was operating the airplane under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the personal cross-country flight that originated from Blanding, Utah, approximately 2 hours before the accident. No flight plan had been filed. The pilot said he had the airplane topped off with fuel prior to departure from Salt Lake City 2 days before the accident. He flew to Blanding, Utah, for Christmas celebrations with family members. The flight lasted approximately 2 hours and 15 minutes. Prior to departure from Blanding, the pilot said he visually checked the fuel tanks and fuel gauges. "One registered just under 20 gallons and the other 15 gallons." The pilot said he calculated his fuel burn at 9 gallons per hour. He did not take on additional fuel before departure. The pilot said that about half way between Price and Provo, Utah, the engine lost power. He said he enriched the mixture, activated the electric fuel pump, and switched fuel tanks. The engine's power increased. The pilot said he decided to head toward Spanish Fork Canyon. Shortly thereafter, with the Spanish Fork Airport in sight, the engine again lost power. The pilot performed a forced landing to an open, plowed field. During the landing roll, the airplane nosed over bending both wings, the vertical stabilizer, and the firewall. Postaccident examination of the terrain revealed that it was frozen hard. An FAA inspector retrieved approximately 1/4 cup of fuel from one fuel tank, and he reported that other tank was empty. The inspector also said the fuel strainers were clean, but dry. According to the Pilot's Operating Handbook, the airplane has 48 gallons of usable fuel capacity. The Hobbs meter in the airplane reflected a total time from Salt Lake City to Blanding, and from Blanding to the accident site, as 5.2 hours. This results in an average fuel burn rate of approximately 9.3 gallons per hour.