The airplane sustained substantial damage following a landing gear collapse during the landing roll at 1248 Mountain time. The private pilot was not injured. Visual conditions prevailed. According to the pilot, he approached the airport and attempted to extend the landing gear, which did not extend. He then reset the circuit breaker and extended the gear, confirming with a green light. The airplane touched down and, approximately 50 yards down the runway, the landing gear collapsed. This event was upgraded to an accident after an FAA inspector verified structural damage on the underside of the fuselage.