On September 1, 2002, about 1900 Alaska daylight time, a tundra tire-equipped Piper PA-18 airplane, N6981B, sustained substantial damage when the airplane collided with a ditch during an overrun while landing at a remote airstrip, about 32 miles west of Anchorage, Alaska. The airplane was being operated as a Title 14, CFR Part 91 visual flight rules (VFR) cross-country personal flight when the accident occurred. The airplane was operated by the pilot. The private certificated pilot, and the sole passenger, were not injured. Visual meteorological conditions prevailed. The flight originated at the Lake Hood Strip, Anchorage, about 1830. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on September 4, the pilot reported that he was landing near the top of Little Mount Susitna. The landing strip, oriented southeast/northwest, is about 600 feet long, by 15 feet wide, and is positioned on a ridge of the mountain. The pilot said he was landing toward the southeast, but touched down on the strip about 1/3 of its total distance beyond the landing threshold. He applied the airplane brakes, but the airplane tires began to slide on wet grass. The airplane departed off the end of the landing strip into an area of low bushes on a down sloping portion of the landing area. The left main landing gear tire struck a hole about 300 feet past the end of the landing strip. The airplane's left main landing gear was sheared off. The pilot reported that after the accident, he utilized a hand-held wind meter, and discovered about a five knot tailwind. The airplane received damage to the propeller and the left wing lift strut. Additionally, the outboard end of the left wing was bent upward about 20 degrees. The Pilot/Operator Aircraft Accident/Incident Report (NTSB Form 6120.1) submitted by the pilot, contained an optional area for recommendations as to how the accident could have been prevented. The pilot indicated that his recommendation was, "Perform go-around instead of landing long."