The pilot was landing a tundra-tire and tailwheel-equipped airplane on a short, wet off-airport site that is on the top of a small butte. He was unable to stop the airplane in the available landing area, and the airplane rolled over an embankment, coming to rest approximately 50 feet downhill in a shallow creek bed. The airplane sustained substantial damage to both wings. The pilot indicated there were no preaccident mechanical anomalies with the airplane that would have precluded normal operation.
A completed copy of NTSB Form 6120.1, Pilot/Operator Accident Report, was not submitted by the pilot as requested.