The airplane was substantially damaged during an off-airport forced landing at about 1424 Pacific time. The pilot received minor injuries. After departing with full fuel and flying about two hours in cruise at 9500 feet msl, the pilot detected irregularities with the indicated fuel quantities for some of the fuel tanks. He switched fuel tanks several times, but soon thereafter the engine quit, and he executed a gear-up forced landing in the desert. Both wings and the stabilator were impact-damaged, and one propeller blade was bent aft at the mid-span location. The airplane had a total usable fuel quantity of 88 gallons. According to the pilot, he had about 2300 hours of experience in the accident airplane make and model. Recorded weather observations at two airports near the accident site indicated visual conditions existed.