The commercial pilot stated that he was flying a Beech B100 on a visual approach to runway 33, a 3,210-foot long, 75-foot-wide, asphalt runway. The approach was executed with full flap extension, and the landing gear extended. The right main landing gear touched down approximately 2 feet prior to the runway, and collapsed as it traveled over the elevated runway edge. The airplane subsequently came to rest upright off the right side of the runway. The pilot did not report any pre-impact mechanical malfunctions with the airplane.