On Sunday, May 2, 2004, approximately 1600 Pacific daylight time, a SZD Jantar 42-1 glider, N272AS, collided with young trees during a forced landing about six miles southeast of Wamic, Oregon. The commercial pilot, who was the sole occupant of the aircraft, was not injured, but the aircraft, which is owned and operated by the pilot, sustained substantial damage. The 14 CFR Part 91 personal pleasure flight, which departed Hood River, Oregon, about three hours earlier, was being operated in visual meteorological conditions. No flight plan had been filed. According to the pilot, he was beginning to work his way north toward Hood River for landing, when he encountered an area where there was not sufficient lift to keep the glider at an altitude that would allow him to continue along his intended route. As the glider descended, the pilot headed toward an area where he knew there was a small airstrip that he would be able to land on. Once the aircraft descended to a height of about 300 feet above the ground, the pilot realized that he could not safely continue en route, so he made the decision that he should commit to the best nearby landing area he could find. Since he was at that time over terrain that was almost completely covered by trees, he selected an area of young/small trees, and flew the glider onto them at a very slow airspeed in an attempt to execute a controlled crash landing. After impacting the trees, the glider slid to the ground, and the pilot exited in a normal manner.