The pilot in the tailwheel-equipped airplane reported that, during landing, the airplane encountered a "strong" wind gust. The airplane touched down on the left side of the runway centerline. The pilot stated that, when the tailwheel touched down, it felt as though the airplane was being pushed further to the left side of the runway. He recalled that the right wing lifted, and the airplane veered left. He applied right rudder, and he leveled the wings, but the airplane exited the left side of the runway and impacted a culvert. The airplane sustained substantial damage to the right wing. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. The METAR for the airport reported that, about the time of the accident, the wind was from 260° at 11 knots, gusting to 16 knots. The pilot landed the airplane on runway 25.