On April 25, 1999, at 1350 central daylight time (cdt), a Cessna 172M, N64373, operated by a student pilot, was substantially damaged when on landing the airplane departed the runway and impacted into a ditch. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under 14 CFR part 91. No flight plan was on file. The student pilot reported sustaining minor injuries. The cross-country flight originated at West Chicago, Illinois, at 1320 cdt. The student pilot said that he was going to land at Grand Geneva Airport, Lake Geneva, Wisconsin. He said that after touching down and rolling out on the runway, he encountered a gust of wind and lost directional control to the left. The airplane went off of the side of the runway. A Federal Aviation Administration (FAA) inspector examined the airplane at the scene. The airplane was found resting upright, with the nose and propeller buried in a ditch approximately 100 feet left of the prepared surface of runway 23 (4,100 X 75) at Grand Geneva Airport. The airplane had departed the runway approximately 1,000 feet down from the approach end. The airplane's nose gear was broken aft. The right wing was bent aft at the wing root. The right wing tip was broken. The right flap was bent. The right rear and side windows were broken inward. The left wing was bent aft at the wing tip. The left wing leading edge was pushed inward 3 inches at the pitot tube. Flight control continuity was confirmed. Examination of the airplane's engine, engine controls, and other airplane systems revealed no anomalies. At 1345 cdt, the Aviation Routine Weather Report (METAR) at Janesville, Wisconsin, located 30 miles west of the accident site, reported surface winds of 180 degrees magnetic at 7 knots. At 1353 cst, the METAR at Kenosha, Wisconsin, located 19 miles east of the accident site, reported surface winds of 180 degrees magnetic at 8 knots.