On May 5, 1994, at 1700 central daylight time, a North American T-6G, N3715G, operated by Richard P. James, nosed over after traveling into rough terrain while landing on runway 18 (2,940' x 32') at the Sauk Prairie Airport, Prairie Du Sac, Wisconsin, while on a personal flight. Visual meteorological conditions prevailed and no flight plan was filed. The airplane was substantially damaged and the pilot received minor injuries. The flight originated from Boscobel, Wisconsin, on May 5, 1994, at 1640 cdt. The pilot stated he circled the airport and noticed a "definite" crosswind from the west at 12 to 15 knots. He stated he then made one low pass and was able to maintain the runway heading using 2/3 of the available rudder control so he decided to land using full flaps. The pilot stated he touched down on the main gear and as the tailwheel began to settle, a "right swerve rapidly developed." The pilot stated he stopped the ground loop using left rudder and brake along with power; however, the airplane was headed toward a freshly plowed field next to the runway. The airplane traveled into the field where the main gear dug into the soft terrain and the airplane nosed over.