On October 13, 1997, at 0855 hours mountain standard time, a Cessna 150, N71VL, collided with a dirt berm during a forced landing following a engine failure about 30 nautical miles north of Temple Bar, Arizona. The aircraft sustained substantial damage. The commercial pilot and his passenger were not injured. The aircraft was being operated as a personal flight under 14 CFR Part 91 when the accident occurred. The flight originated in St. George, Utah, at 0655. Visual meteorological conditions prevailed at the accident site. The pilot estimated that they were approximately 800 feet above ground level when the engine suddenly quit. He said that they were "fairly low level in order to spot game," and had started a turn to the left when the engine quit. The pilot said that the engine started "sputtering" for a second or two during the descent and then quit. He told investigators that "it acted like it was out of gas." The Mojave County Sheriff's office examined the airplane after the accident at the request of the Safety Board. The examination revealed that there was zero fuel in the left tank and approximately 1 1/2 inches of fuel in the right tank. The Sheriff's office reported that the aircraft came to rest in an nose-down attitude in a left bank approximately 20 to 25 degrees. The aircraft was recovered and examined at the direction of the Safety Board. The inspector that examined the aircraft noted that the top spark plugs burned very lean and that the mixture control was found approximately 1 inch pulled out from the panel. The fuel gascolator bowl was dry with very little residue at the bottom of the bowl. The inspector also noted that during the aircraft recovery proceeding, a total of 3 gallons of fuel was drained from the fuel system at the accident site as routine procedure before transporting the wreckage to a secure location. The pilot reported that he performed a preflight on the aircraft the morning of the accident and noted that it needed fuel. He stated that he was unable to obtain any aviation fuel, and that the owner of the airplane had told him he could put automotive fuel in the airplane. He said he proceeded to put "approximately 8 gallons in the airplane." The pilot said he performed a "stick test" of the airplane and determined that "one side showed 10 gallons and the other just over 10.5 gallons of useable fuel." According to the Cessna factory representative who was consulted on the circumstances surrounding this accident, the 3 gallons of fuel that was drained out of the fuel tanks represents fuel that is under the useable level. According to the Cessna 150 Owner's Manual, with the fuel quantity indicators reading empty there is 1.75 gallons unusable in each standard tank.