On August 2, 2015, about 1910 mountain daylight time (MDT), a Piper PA 28-181, N7963C, made an off airport landing following a loss of engine power near American Falls, Idaho. Aspen Flying Club was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The private pilot and two passengers were not injured. The airplane sustained substantial damage to the left wing during the accident sequence. The cross-country personal flight departed Lincoln (KLHM), California, at 1430 MDT (1330 Pacific daylight time) with a planned destination of Idaho Falls, Idaho. Visual meteorological conditions (VMC) prevailed, and no flight plan had been filed. During the multi-leg cross-country trip, the pilot reported that he had trouble starting the engine in Santa Monica, California. Maintenance personnel discovered fouled spark plugs, and cleaned them. On the day of the accident, the pilot departed San Francisco, California, and stopped for fuel in Lincoln. The pilot stated that with full tanks the airplane could fly 5-5.5 hours, and he intended the next fuel stop to be 4.5 hours later at Idaho Falls. He was receiving visual flight rules (VFR) flight following from the Salt Lake City Air Route Traffic Control Center (ZLC ARTCC). Four hours into the flight, the pilot determined that the groundspeed was less than planned. The left fuel tank indicated 5 gallons, and the right indicated more than 5 gallons, so the pilot estimated that there was enough fuel for 1 more hour of flight. The airplane was over the Burley, Idaho, airport, but he was unfamiliar with it. He decided to continue to Pocatello, Idaho, and figured that he would arrive there with enough fuel for an additional 30-45 minutes of flight. About 10 miles and 3-5 minutes from Pocatello, the right fuel tank indicated empty and the left tank 2-5 gallons with the indicator shaking. This was 4 hours 40 minutes into the flight, and then the engine stopped. A nearby road had power lines near it, so the pilot elected to land in a field. The main landing gear separated; the left wing sustained substantial damage, and the nose gear was crushed upwards. After the landing, the pilot noted that the left fuel gauge still indicated 5 gallons. A Federal Aviation Administration (FAA) inspector examined the wreckage at the recovery facility in Boise, Idaho, and a full report is in the public docket. Recovery personnel reported that the fuel tanks were not breached, and they drained no fuel from either wing tank, and a few ounces from the gascolator. The inspector obtained thumb compression on all cylinders. All spark plugs were grey except a slight oil film on the bottom plugs for cylinders two and four. There was no abnormal wear, fouling, or burn patterns on the spark plug electrodes. The gascolator screen and bowl showed no evidence of corrosion or contaminants. Upon removal of the hose and end clamp to the electric fuel pump, about 1 teaspoon of fuel flowed from the hose. About 2 ounces of clean, light blue fuel drained out of the carburetor fuel bowl drain plug when it was removed. The carburetor internal finger screen contained light contamination. He observed no anomalies that would have precluded normal operation of the engine. The 23-year-old pilot had 92 hours total flight experience with 50 hours as pilot-in-command and 26 hours in type.