On August 21, 1994, at 0945 Alaska daylight time, a wheel equipped Cessna 150 airplane, N2677J, registered to and operated by the Pilot, struck the trees at the end of the Johnson River Airstrip during takeoff. The airstrip is located 40 nautical miles east of Big Delta, Alaska. The personal flight, operating under 14 CFR Part 91, was departing the Johnson River Airstrip and the destination was Delta Junction. No flight plan was filed and visual meteorological conditions prevailed. The pilot and his passenger were not injured and the airplane was substantially damaged. According to the pilot, he took off from the 850 foot long airstrip and struck the trees at the opposite end. The airplane lost airspeed and he stalled. The airplane descended through the trees uncontrolled. Records show that the pilot has not had a current medical certificate since 1983. He was denied a medical based upon high blood pressure. The pilot did not complete a Biennial Flight Review as required by Federal Aviation Regulations. According to the Cessna 150 owner's manual, the take off ground run distance required for the altitude and temperature described by the pilot was 910 feet. To clear a 50 foot obstacle required a distance of 1660 feet.