On August 4, 1994, about 1330 Alaska daylight time, a tundra tire equipped Piper PA-18, N339T, collided with terrain during takeoff about 30 miles northeast of Circle, Alaska. The airplane was being operated as a visual flight rules (VFR) cross-country personal flight to Circle when the accident occurred. The airplane operated by the pilot, received substantial damage. The certificated private pilot and the sole passenger received minor injuries. Visual meteorological conditions prevailed. The pilot reported that he landed on a remote gravel bar along the banks of the Little Black River the day before the accident. He indicated that he had landed on the same section of the river numerous times in the past. The strip was about 650 feet long and water was present at both ends of the area. The pilot indicated that he applied full power for takeoff on a heading of about 200 degrees. After rolling about 300 feet, the airplane became light and after approximately 400 feet of departure roll, he added flaps. The airplane lifted off but then settled back to the ground and bounced off an open section of water. The airplane's right main landing gear struck a log and the right wingtip contacted a small river bank. The airplane came to rest facing 180 degrees from the departure heading.