According to the pilot in the tailwheel-equipped biplane, he was unable to determine the wind direction during his approach. He circled the airport multiple times and attempted to communicate on the common advisory traffic frequency. During the landing roll on the runway, the biplane experienced an "unexpected turn to (the) left similar to being weathercocked." The biplane exited the left side of the runway and continued across descending terrain before it nosed over. The METAR nearest to the accident airport reported that, about the time of the accident, the wind was from 170° at 16 knots, gusting to 19 knots. The biplane sustained substantial damage to both wings and the rudder. The pilot reported that there were no preaccident mechanical malfunctions or failures with the biplane that would have precluded normal operation.