On September 16, 2011, about 1000 mountain daylight time, a Cessna 182H, N1843X, sustained substantial damage during a forced landing following a loss of engine power near Paragonah, Utah. The private pilot received minor injuries, and three passengers were not injured. The owner/pilot was operating the airplane under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the personal cross-country flight, which had originated approximately 1 hour 45 minutes before the accident. A flight plan had not been filed. According to the pilot, the airplane was in cruise flight when the engine lost power. He performed a forced landing to a road, but, during the landing roll, he noticed a vehicle coming towards him. He turned the airplane to the right off the road, through a fence, and into an adjacent field. The left wing, fuselage, and firewall were bent and wrinkled. A local law enforcement officer examined the airplane immediately after the accident and found both fuel tanks empty. He also noted that the left fuel tank’s cap was missing. The pilot reported finding the fuel cap 3 days later, in the run-up area at his departure airport. The pilot stated that he had filled up both fuel tanks before beginning the flight, and that he either did not replace the fuel cap or left it loose following the refueling.