The glider collided with trees while the pilot was attempting an off airport landing. The glider was towed to an altitude of 3,000 feet and released. The pilot flew around a ridgeline for about 30 minutes, and when the lift dissipated, he elected to attempt a landing in a corn field. During the base to final approach turn, the glider impacted trees prior to coming to rest in the field. The outboard 6 feet of the glider's left wing separated, and the fuselage was damaged. The pilot reported that he extended the downwind leg too far, and did not compensate adequately for winds. Winds were reported about the time of the accident, at an airport located 22 miles north of the accident site, from 290 degrees at 8 knots. The pilot reported 3,400 hours of total glider flight experience, which included about 300 hours in the same make and model as the accident glider.