On December 24, 1999, at 1600 central standard time, a Beech BE-35, N2012D, was substantially damaged when the main landing gear collapsed during a forced landing in a field near Mokane, Missouri. The airplane was at cruise flight at 3,500 feet mean sea level when the engine sputtered and quit. The 14 CFR Part 91 personal flight had originated from Montgomery-Wehrman Airport, Montgomery City, Missouri, (4MO) at 1510 and was on a local flight. The private pilot and two passengers were not injured. Visual meteorological conditions prevailed and no flight plan was filed. The pilot reported that after the engine quit he scanned the gauges. He reported the left fuel tank indicated 1/4 tank of fuel. The pilot reported that the left fuel tank was selected, but he did not change the fuel selector to the right fuel tank when he tried to perform an engine re-start. The pilot pulled the Carburetor Heat-On but it had no effect. The pilot executed a forced landing in a field, but the landing gear collapsed during landing rollout. The pilot reported the airplane, "... bounced over a drainage ditch in the field and then the nose wheel hit the ground and broke off." The pilot reported he inspected the left wing tank for fuel. He reported he, "couldn't see gas in the tank," and that the left tank was "pretty empty." He checked the right tank and estimated there was 3 to 4 gallons of fuel in the right tank. He reported the right fuel gauge indicated 1/4 tank. The pilot reported he had fueled the airplane with approximately one hour of fuel in each tank. He reported that he had flown for approximately one hour when the engine quit. The airplane's flight manual lists "(1) Select other fuel tank (check to feel detent)" as a step in the emergency procedures for loss of engine power.