On August 1, 1997, at 1320 central daylight time (cdt), a Young RV-4, N654Y, operated by a commercial pilot collided with the terrain while landing on runway 19 (4,295' x 100') at the Fort McCoy Airport, Sparta, Wisconsin. The 14 CFR Part 91 flight was operating in visual meteorological conditions without a flight plan. The airplane was substantially damaged. The pilot and passenger were not injured. The flight originated from Yankton, South Dakota, at approximately 1100 cdt. The pilot reported he was intending to land at Sparta for fuel while en route to Oshkosh. He reported that he chose to make a wheel landing since the wind was greater than 10 knots and not directly down the runway. The pilot continued to report that upon landing, a gust of wind was encountered and the airplane bounced. He applied power, but the airplane bounced one more time. He reported he then added full power to perform a go- around but the engine was vibrating from the propeller having struck the runway. He reported, "I immediately went to idle power and attempted to lower the nose but suspect I stalled." The airplane descended and impacted the terrain off the right side of the runway.