On July 4, 1997, at 1250 hours Pacific daylight time, a Cessna 182A, N2011G, lost power and collided with rocks while performing a forced landing 1 mile east of the Santa Paula, California, airport. The aircraft was substantially damaged, and the owner/pilot received minor injuries. Visual meteorological conditions existed for the personal flight. The flight originated from the Santa Maria, California, airport at 1145 and was to terminate at the Whiteman, California, airport. The pilot stated he was en route and decided to land at Santa Paula in order to refuel the aircraft with 80 octane aviation gasoline. During the descent at 4,000 feet mean sea level (msl), the engine lost power and there was insufficient altitude to make the runway at Santa Paula. The aircraft landed in a river bed and collided with rocks and other obstacles. In an interview with an Federal Aviation Administration (FAA) airworthiness inspector from the Van Nuys, California, Flight Standards District Office, the pilot stated that during the preflight inspection a calibrated instrument was used to dip the tanks, and that the aircraft had approximately 7 gallons in the right tank and 9 gallons in the left tank. The pilot did not describe the nature of the "calibrated instrument," nor how the device was calibrated to the fuel tanks on this aircraft. On initial run-up the engine sounded rough, but then ran normally before takeoff. The pilot stated that on takeoff the fuel selector valve was set to the left tank and shortly after takeoff he switched it to the right tank. The pilot reported that he ran the right tank dry (engine quit) and switched to the left tank and began a circling descent to Santa Paula because he knew he was low on fuel. The engine ran approximately 5 more minutes and then lost power again. Attempts to restart the engine, including switching the fuel selector positions, were unsuccessful. The pilot reported that the engine was running normally prior to the accident and that he knew of nothing wrong. The FAA inspector asked the pilot if he had run out of fuel and the pilot reported that "technically, yes he ran out of fuel." According to excerpts from the Cessna Aircraft Company's Cessna Skylane and 182 Owner's Manual page 1-8, each tank holds approximately 32.5 gallons of fuel; 1.5 of which is unusable fuel in each tank, for a total of 3 gallons being unusable. On page 6-3, the Skylane cruise and range performance chart notes that for an altitude of 2,500 feet above ground level (agl) the fuel consumption rate is approximately 12 gallons per hour. With a total of 13 gallons of useable fuel in both tanks, the pilot would have been able to fly his aircraft approximately 1 hour in a calm wind condition. Santa Maria airport is 76.5 nautical miles from the Santa Paula airport, in calm wind conditions it is approximately a 30-minute flight. An FAA inspector from the Van Nuys, California, Flight Standards District Office, examined the aircraft on site the day of the accident. He reported that the fuel system appeared to be intact and there was no fuel in either of the tanks. No other mechanical anomalies were noted with the aircraft.