On August 23, 1995, at 2130 Alaska daylight time, a wheel equipped Cessna 172 airplane, N96911, registered to and operated by the pilot, crashed into trees during maneuvering flight near Harvey Lake, Alaska. Harvey Lake is located approximately 25 miles east, southeast of Kenai, Alaska. The personal flight, operating under 14 CFR Part 91, departed the Soldotna Airport for a local flight. A visual flight rules flight plan was filed and visual meteorological conditions prevailed. The private certificated pilot and two passengers were not injured. One passenger was seriously injured. The airplane was substantially damaged. During a telephone conversation with the pilot on August 25, 1995, he stated he was flying upslope into a valley at 80 knots indicated airspeed and with 10 degrees of flaps extended. The airplane was not climbing as he expected and he attempted to turn to reverse direction and fly downhill. Approximately 3/4 of the way through the turn, the right wing struck a tree. The airplane decelerated and struck more trees and crashed into the alder bushes. The pilot stated they were attempting to spot game for a future hunting trip. According to the pilot's statement attached to the NTSB Form 6120.1/2, the pilot stated that during the turn the airplane's stall warning horn was sounding. He also said that the wind was blowing approximately 15 knots based upon his observation of the moving tree tops. He stated that the wind blowing over the "bench" (flat area on a mountain slope) created a downdraft which affected the airplane's ability to climb.