On September 8, 2007, about 0900 mountain daylight time, a Cessna 182G, N2420R, sustained substantial damage during a forced landing following a loss of engine power approximately 20 miles north of Fairfield, Idaho. The private pilot and the passenger were not injured. The pilot was operating the airplane as a 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed and no flight plan was filed for the local flight that departed from Twin Falls, Idaho, about 0700. According to the pilot, the purpose of the flight was to spot elk. During his pre-flight inspection, he did not visually check the quantity of fuel in the airplane's tanks. He stated that he had filled the airplane with fuel two days prior to the day of the accident. He further stated that at the time of takeoff, both tanks registered full on the fuel gauges. Approximately 2 hours into the flight, the engine lost power, and the pilot executed a forced landing to a clearing filled with sand, gravel and brush. During the landing roll, the nose wheel sank into the sand, and the nose landing gear separated. The airplane sustained damage to the firewall and to the bottom fuselage structure. An FAA inspector examined the airplane at the accident site and found no fuel in either the left or right fuel tank or in the header tank just forward of the firewall. Additionally, no fuel was present at the fuel injector spider on top of the engine. The inspector noted no evidence of fuel leakage onto the ground at the accident site or on the outer skins of the airplane. When power was applied, the fuel gauges indicated empty.