On September 3, 1995, approximately 1500 Pacific daylight time, a Cessna 150, N4016J, sustained substantial damage when it collided with trees and terrain after takeoff from the Stehekin, Washington, airport. The private pilot and his passenger sustained minor injuries. No flight plan was filed for the flight. There was no fire and no report of the ELT actuating. After the accident, the pilot stated to a pilot-rated National Park Service employee that during takeoff, just above the tree line, the aircraft settled into the tree tops. Additionally, the pilot stated that he couldn't get lift out of ground effect; the aircraft did not stall, and there were no powerplant problems. The Park Service employee noted that winds were calm and the temperature was about 85-90 degrees Fahrenheit, and that the pilot took off uphill to the northwest. According to information provided by the pilot, the Stehekin airport runway is approximately 2700 feet long, with about 600 feet of overrun area on the northwest end of the departure runway, with 150 foot tree tops in a forested area at the end of the overrun. According to topographic chart information, the departure end of runway 33 is over 30 feet higher than the approach end. The pilot stated that after runup, he applied full power and released the brakes. He rotated about 50 mph with 1200 feet of runway remaining, establishing a 58-60 mph climb. He said he climbed to approximately 150 feet AGL by the end of the usable runway and reached approximately 200 feet AGL, or 50 feet above tree level upon reaching the end of the runway overrun. He stated that within seconds of passing the runway overrun, the stall warning sounded and the airplane was pitched down to regain airspeed. Airspeed continued to bleed off and altitude was being lost. He stated that the situation was indicative of a tail wind shear/gust and he elected to prepare for a forced landing since continued climb was not possible. He said he lowered 10 degrees of flaps and remained at full power. The airplane contacted tree tops on both wings. The airplane came to rest on its left wing tip and with the bottom of the fuselage resting against the trunk of a tree. A review of the owners manual for the aircraft revealed that no data is provided for takeoff performance on runways other than level.