On April 11, 2006, approximately 1330 mountain daylight time, a Cessna TR182 single engine airplane, N729SC, sustained substantial damage when it impacted terrain during a forced landing, following a loss of engine power in cruise flight, near Fort Collins, Colorado. The private pilot, who was the sole occupant and registered owner of the airplane, was not injured. Visual meteorological conditions prevailed, and a visual flight rules flight plan was filed for the Title 14 Code of Federal Regulations Part 91 personal flight. The flight departed Carlsbad (CNM), New Mexico, at 0925, and was en route to Laramie (LAR), Wyoming. According to the pilot, prior to departure from LAR to CNM on April 9, 2006, the pilot topped of the fuel tanks. After his arrival at CNM, the pilot conducted a short flight with a family member. The pilot reported that his total flight time for that day was 4.5 hours. Prior to departure back to LAR, the pilot requested the fixed based operator fuel attendant to add fuel to the right tank. The pilot stated, "I learned that the price of avgas was considerably higher at CNM than at my home base, so I asked the attendant to add 30 gallons to the right tank only... In this particular aircraft when it is flown with the fuel selector in the 'both' position, the right tank always drops down below about half full before you begin to see any drop in the left tank, and after a long trip it is always the case that more fuel needs to be added to the right tank... My calculations were: based on 92 gallons capacity, I should have about 40 gallons remaining prior to adding 30 gallons at CNM, for a total of 70 [gallons], and I planned to use about 50 [gallons] on the return trip." While in cruise flight at 10,500 feet, the pilot encountered light and occasional moderate turbulence. Because of the turbulence, the pilot reduced the engine power several times to slow the aircraft. At least three times during the flight, the pilot lowered the landing gear to slow the aircraft and to increase stability. Near the Denver terminal area, the pilot descended to 8,500 feet until he needed to climb between Fort Collins and LAR. Shortly after passing the Greeley, Colorado, airport to the north, the engine lost power. The pilot noticed on the fuel gauges that the right tank appeared empty and the left tank indicated more than 1/4 tank of fuel. The pilot switched the fuel selector to the left tank and the engine regained power. The pilot then decided to land at Fort Collins Downtown Airport (3V5) to add some fuel, check the magnetos and ground run the engine before continuing to LAR. Approximately 9 miles from 3V5, the pilot lowered the landing gear and initiated a descent to 3V5 pattern altitude. During the descent, the engine "faltered and surged" 4 to 5 times. The pilot then trimmed the airplane for a 60 knot glide speed, declared an emergency on UNICOM frequency and attempted a landing to runway 29 at 3V5. Shortly thereafter, the engine lost power, and the pilot initiated a forced landing to a field. During the forced landing, the airplane contacted a fence and a berm, and the nose gear collapsed, buckling the firewall. The total time on the HOBBS meter from the April 9th departure from LAR to the time of the accident was 8.8 hours. According to the NTSB Aircraft Accident Report Form (NTSB Form 6120.1), Recommendation (How could this accident have been prevented?) section, the pilot listed the following recommendations: 1. Manually checking fuel supply remaining with a dipstick rather than relying on hourly rate of use (at CNM). 2. Topping off the tanks at CNM rather than leaving with partial fuel due to high fuel cost. 3. Once engine faltered the first time, immediately initiate the off-airport landing. The field was large enough that with a careful approach and touchdown at one edge I could have stopped before the fence. 4. Not letting the fuel gauge lull me into believing my previous estimates. Closer and more frequent monitoring might have made me aware that the gauge was not dropping. On April 18, 2006, the pilot submitted to the NTSB investigator-in-charge (IIC) the following amendment to the NTSB Form 6120.1. "On page 6, Mechanical Malfunction: The fuel gauge for the left tank was showing between 1/4 and 1/2 full at the time of engine stoppage due to apparent fuel exhaustion. This was a contributing cause to the accident/incident, in that I had estimated I would have approximately 15-20 gallons remaining at that time, and the fuel gauge seemed to confirm my estimate." During the recovery of the airplane from the field, Beegles Aircraft Services personnel removed the wings for transport. According to the recovery personnel, less than 1 gallon of fuel was recovered from the wing tanks and airframe fuel lines. The NTSB IIC and a Beegles mechanic removed the fuel sending units from the wings and functionally tested the units by connecting them to their respective wiring harness on the airframe. A functional check of the sending units and cockpit fuel gauges revealed no anomalies.