On August 14, 1994, at 1323 hours mountain daylight time (MDT), a Grob G-109B motorized glider, N45GF, recently purchased and being flown by Bonny L. Feather, a private pilot, was substantially damaged during collision with terrain during takeoff from runway 9 at the Rock Springs Municipal Airport, Rock Springs, Wyoming. The pilot received serious injuries. Visual meteorological conditions existed with gusting winds and no flight plan was filed. The flight, which was personal in nature, was to have been conducted in accordance with 14CFR91, and was destined for Cheyenne, Wyoming. In a written statement, the pilot reported that the takeoff roll was normal and directional control was easily maintained. The tail wheel lifted off at 24 to 26 knots and the glider weather cocked to the left. The pilot countered with right rudder control and left wing down. The glider lifted off and began drifting to the left side of the runway at approximately three feet above ground level. The pilot stated that the glider may have touched sage brush before drifting back over the runway and to the right side. The glider then collided with the sage brush and subsequently the ground. A witness at the airport stated that it appeared that the glider was having difficulty gaining altitude after takeoff from runway 9. The witness observed the glider make one complete 360 degree left turn and then start another turn before he saw it collide with the terrain. The witness stated that he did not notice any "dust devils" or unusual wind conditions at the time of the accident. The witness did note the weather conditions and reported the winds from 30 degrees at ten knots, gusting to 17. The temperature was 81 degrees, and atmospheric pressure was 30.40" Hg. Density altitude was calculated at 9,180 feet. The pilot reported that there were no mechanical failures or malfunctions with the glider at the time of the accident.