On June 14, 2001, at approximately 1200 central daylight time, a Smith Aerostar 600, N7484S, operated by a private pilot, sustained substantial damage during landing on runway 28 (2,740 feet by 90 feet, dry asphalt) at the Three Castles Airpark (4D1), Wonewoc, Wisconsin, when it struck a deer. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under the provisions of 14 CFR Part 91 without a flight plan. The pilot reported no injuries. The cross-country flight originated at Kenosha, Wisconsin, at 1100, and was en route to Wonewoc, Wisconsin. In his written statement, the pilot said he was landing on runway 28 at 4D1 following a 50 minute flight. As the main landing gear wheels were touching down on the runway, he hit a deer. The airplane rolled down the runway normally and was slowed. The pilot said that he couldn't turn the nose wheel to exit the runway. A Federal Aviation Administration inspector examined the airplane at the 4D1. The nose gear trunion was bent rearward. The aft bulkhead of the forward wheel well was bent inward. The forward pressure bulkhead and right forward cabin wall near the pilot's rudder pedals were bent inward. The cabin floor beneath the control pedestal was bent upward. Flight control continuity was confirmed. An examination of the airplane's engines, engine controls and other systems revealed no anomalies.