On August 11, 1996, at 1215 central daylight time, a Cessna 210E, N4963U, operated by a commercial pilot collided with the terrain during an off airport forced landing in Clarksville, Missouri. The forced landing in a bean field resulted as a loss of engine power. The pilot and passenger were not injured. The airplane was substantially damaged. The 14 CFR Part 91 personal flight was operating in visual meteorological conditions on an IFR flight plan. The flight originated from Camdenton, Missouri, at 1110 cdt. The pilot reported the airplane had been topped off with 25 gallons of fuel on the previous day. He reported that approximately one hour into the flight, the engine lost power and began to run rough at which time he noticed the fuel flow decreased to 4 gph. He stated he enriched the fuel mixture, switched fuel tanks and turned on the boost pump. He reported that the fuel flow momentarily increased to 12 gph prior to dropping back down. The pilot stated that with the boost pump on, a strong odor of fuel was present in the cockpit. Unable to regain engine power, the pilot initially selected a county road on which to land, but due to cars on the road he landed in a bean field. The pilot reported that the bean field was slightly uphill and the nose gear separated from the airplane during the landing. He stated the airplane slid on the nose cowl and the right wing tip prior to coming to a stop. Post accident inspection of the wreckage by an inspector from the Federal Aviation Administration Kansas City Flight Standards District Office revealed the right wing fuel tank was 1/2 to 3/4 full of fuel and the left wing fuel tank was empty. He reported the fuel selector was selected to the left tank. No anomalies with the fuel system or engine were discovered which would have resulted in the loss of engine power.