On July 31, 1999, about 1910 Alaska daylight time, a tundra tire equipped Piper PA-18 airplane, N693JB, sustained substantial damage when it nosed over during landing at an off airport landing site, about 10 miles west of Levelock, Alaska. The solo commercial pilot was not injured. The business flight was operated under 14 CFR Part 91 by RDM Pilot/Guide, Ltd., of Anchorage, Alaska. The flight departed King Salmon, Alaska, at 1900 to look for game. Visual meteorological conditions prevailed at the time of the accident, and a company VFR flight plan was filed. The pilot told the NTSB investigator-in-charge during a telephone interview on August 6, and wrote in his NTSB Pilot/Operator report, that during an off airport landing on tundra, the airplane nosed over. The left wing tip rib, and the overhead crossbar in the cabin roof, were damaged. He indicated there were no preaccident anomalies with the airplane.