On December 6, 2003, at 1030 central standard time, an amateur-built experimental biplane Clement-Kazmierczak Sorrell SNS-7 airplane, N7543E, piloted by a private pilot, was substantially damaged when it hit a snow bank and nosed over during landing. The accident occurred at a private airstrip (2,500 feet by 75 feet, turf) approximately 15 miles north of Highmore, South Dakota. Visual meteorological conditions prevailed at the time. The flight was operating under 14 CFR Part 91 and was not on a flight plan. The pilot and passenger reported no injuries. The flight departed the Converse County Airport, Douglas, Wyoming, at 0715 mountain standard time, with the private airstrip as the intended destination. In his written statement, the pilot reported that prior to the flight he contacted the owner of the private grass strip to verify runway condition. The owner reportedly indicated that the runway was acceptable for use. The pilot noted that upon arrival the wind was from the southeast about 10 miles per hour. He stated that he set-up and landed to the south. "After landing, I hit a small snowdrift, added power and the plane nosed over," according to the pilot. The pilot reported no failures or malfunctions with the aircraft or engine prior to the accident.