The owner-pilot departed his home airport for a personal flight to another airstrip where he had previously operated many times. Since the turf runway had a significant slope and was bordered by trees on three sides, landings were conducted in the uphill direction, which was to the southeast. The narrowness of the runway, coupled with the proximity of trees to the runway edges, necessitated that pilots taxi uphill to the southeast end, in order to turn around and exit the runway at the northwest end. The pilot overflew the runway to check for deer and other obstacles, and made a left-hand circling approach for the landing to the southeast. There was a slight left crosswind during the approach, but no wind at all on the runway because of the tall trees. Touchdown at the intended landing point, which was about 150 feet beyond the approach end was normal. After landing, the pilot added power to taxi uphill to turn around. However, about 400 feet beyond the touchdown point, the airplane began to drift to the right. The pilot was unable to correct that drift before the right wingtip struck a small tree, which resulted in a sharp right turn. The airplane veered off the right side of the runway, which was a downsloped, wooded area. The airplane was stopped by a large tree, and came to rest approximately perpendicular to the runway, with the tail approximately at the runway edge. The airplane sustained substantial damage to its wings. The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.