On August 16, 1996, about 1200 Alaska daylight time, a wheel equipped Piper PA-18 airplane, N6760B, sustained substantial damage when it collided with trees during an attempted takeoff from a remote gravel bar located in the Nabesna River drainage near Slana, Alaska. The solo private pilot was not injured. The personal, 14 CFR Part 91 flight operated in visual meteorological conditions. During a telephone conversation with the NTSB investigator-in-charge on August 19, the pilot stated that there was a small hump, or gravel swell, in the takeoff area. He said when the airplane encountered the hump, the airplane was forced to the left, and he was unable to maintain directional control. Shortly after passing over the hump, the airplane became airborne. The left wing then collided with a tree and brush, and the airplane subsequently went off the left side of the takeoff area, coming to rest in a stand of trees and brush.