On November 25, 1993, approximately 0950 mountain standard time, N8833T, a Cessna R172K, was substantially damaged during a forced landing about six miles north of Mancos, Colorado. The pilot and two passengers sustained minor injuries. Visual meteorological conditions prevailed for the personal flight. The pilot stated in his enclosed report that during his pre flight inspection he verified that the airplane was fueled to capacity. Westwind Aviation's enclosed report indicated that both fuel tanks were serviced to within three gallons of capacity, which was company procedure, to prevent fuel expansion and venting. The pilot flew with a company instructor for 0.6 hours as part of the rental checkout, then flew from Deer Valley Municipal Airport, Phoenix, Arizona, to Scottsdale, Arizona, Municipal Airport, where he remained overnight. Company officials estimate this flight took 0.4 hours to complete, and that 32.0 gallons were available for the trip to Telluride. The pilot's figures indicate 38.45 gallons were available. The next morning, approximately 0520 Pacific standard time, the pilot and two passengers took off for Telluride, Colorado. Approximately 3.5 hours later, the engine lost power. The pilot made a forced landing and collided with trees. The pilot reported he should have had 5.7 gallons of fuel remaining upon arrival at his destination. Company officials estimated all fuel would have been exhausted. The pilot said that "looking at the fuel gauges is part of my scan, which I run through every few seconds during a flight" and "I do not recall any abnormalities (abnormal fuel consumption) during the latter stages of the flight." A FAA inspector who examined the airplane at the accident site reported that he found no fuel in the right wing tank, and very little fuel in the left wing tank. Draining of both wing sumps and the gascolator yielded residual fuel.