On March 22, 2006, at 1257 central standard time (cst), a Cessna 172G, N4444L, piloted by a commercial pilot, was substantially damaged during a forced landing following a loss of engine power near Collins, Missouri. Visual meteorological conditions prevailed at the time of the accident. The personal flight was operating under the provisions of 14 Code of Federal Regulations (CFR) Part 91 while on an instrument flight rules (IFR) flight plan. The pilot and his three passengers reported no injuries. The flight departed Joe Foss Field Airport (FSD), Sioux Falls, South Dakota, at 0903 cst, and was en route to Springfield-Branson Airport (SGF), Springfield, Missouri. The pilot reported that during cruise flight the engine lost power and he performed a forced landing to a grass field. The airplane's tail section impacted a fencepost and barbed-wire during the forced landing. The pilot reported that he visually confirmed that both fuel tanks were empty after the accident. The airplane's owner reported that the last time the airplane was fully fueled was on March 14, 2006, prior to a 36 minute flight. The airplane was not refueled prior to the accident flight. The pilot reported that the airplane had 34 gallons (31 gallons usable) on-board prior to the accident flight. At 0857 cst, the pilot requested taxi and IFR clearances from FSD air traffic control (ATC). At 0903 cst, the pilot was cleared for takeoff and was subsequently cleared to 7,000 feet mean sea level (msl). At 1254 cst, the pilot reported a loss of engine power and declared an emergency. The elapsed time between the first ATC communication and when the pilot reported the loss of engine power was 3 hours, 57 minutes. The calculated fuel consumption rate for the accident flight was 7.8 gallons/hour. According to the Cessna 172G owners manual, the published fuel consumption rate at 7,500 feet msl and 70% brake horsepower (bhp) was 7.8 gallons/hour. The pilot reported that his preflight planning assumed a fuel consumption rate of 6.1 gallons/hour, at 7,000 feet msl and 2,300 engine rpm (52% bhp). The pilot told a Federal Aviation Administration (FAA) inspector that the fuel quantity gauges had become "erratic" during the accident flight and that he thought they were "unreliable."