The pilot reported that during takeoff to the north east on the dirt airstrip, the tailwheel-equipped airplane began to drift to the left. Despite the pilot's control inputs, the airplane continued to the left, exited the runway, and struck vegetation. The airplane continued to veer to the left as the right main landing gear collapsed. Subsequently, the right wing, horizontal stabilizer, and elevator struck the ground, which resulted in substantial damage. The airplane came to rest on its right side. During a post-accident telephone conversation, the pilot reported that there were no preimpact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation. The pilot estimated that the wind at the time of the accident was from the west at about 5 knots.