On July 6, 2000, about 0940 Eastern Daylight Time, a Cessna U206G, N756HK, operated by Telford Aviation, Inc., was substantially damaged while landing at the Witherspoons Airport (ME41), North Haven, Maine. The certificated airline transport pilot and two passengers were not injured. Visual meteorological conditions prevailed and no flight plan was filed for the on-demand air taxi flight conducted under 14 CFR Part 135. According to the pilot, the flight had originated at the Knox County Regional Airport (RKD), Rockland, Maine, and proceeded uneventfully to ME41. While landing at ME41, on Runway 24, a 1,045-foot long hard packed gravel runway, the pilot reduced the engine power to idle at an altitude of about 100 feet above the ground. The pilot then felt he was "committed" to land and that a go-around with full flaps was unsafe. The airplane touched down, bounced, and began to "float." After the airplane touched down again, the pilot applied the brakes and raised the flaps in an attempt to stop. The airplane continued off the departure end of the runway, crossed a road, struck a boulder, and nosed over into a swamp, coming to rest inverted. When the runway was examined after the accident, a Federal Aviation Administration (FAA) inspector observed skid marks in the gravel that started with 20 feet of runway surface remaining. The inspector also noted that there were trees located at the approach end of the runway and beyond the swamp where the airplane came to rest. The two passengers in the airplane stated to the FAA inspector after the accident that they were coming in "hot and fast." According to the airplane operating handbook, the total landing distance to clear a 50-foot obstacle, using the specified technique for short field landings, at maximum gross weight, at sea level, and at a temperature of 20 degrees Celsius, was 1,415 feet. The pilot reported 8 total hours of flight experience in make and model. The RKD weather at 0935, reported winds from 300 degrees at 11 knots, gusting to 15 knots.