On September 23, 2003, about 1200 Alaska daylight time, a tailwheel-equipped Piper PA-18-150 airplane, N1386A, received substantial damage when it nosed down following a loss of control during an off-airport landing. The accident site was approximately 42 miles northwest of Tanana, Alaska. The solo commercial pilot was not injured. The Title 14, CFR Part 91 business flight was operated by Deltana Outfitters, Inc., in support of a hunt-guide business. The flight departed a remote, private airstrip about 1130, and the destination was the accident site. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight. During a telephone conversation with the National Transportation Safety Board investigator-in-charge on September 25, the pilot of the accident airplane related that the purpose of the flight was to transport moose meat from a gravel bar. The pilot said the surface wind was fairly calm, but there was a 20 knot wind, with gusts to 25 knots, blowing through the trees surrounding the gravel bar, which created significant low level turbulence. He indicated that the airplane touched down on the gravel bar without difficulty, but during the landing roll, a gust of wind lifted the left wing. He elected to abort the landing, and applied full power. He said he was unable to bring the left wing to a level attitude because he could not get full aileron displacement to the left, due to the control stick hitting his left knee. He said when the flap handle was in the down position, it forced his left leg to the right, and consequently restricted movement of the control stick to the left. He was unable to gain full control of the airplane, and reduced engine power to idle. The airplane subsequently went off the end of the gravel bar into shallow water, nosed down, and sustained structural damage to the right wing spar and right aileron. The pilot said there were no preaccident mechanical problems with the airplane.