The glider pilot reported that, after soaring atop local ridgelines, he initiated an approach. During final, the pilot put the airplane in a slip to lose altitude and intercept an "appropriate glideslope." However, the glider's right wing collided with treetops and the glider came to rest inverted.

The airplane sustained substantial damage to the right wing and fuselage.

The pilot reported that there were no mechanical malfunctions or failures with the airplane that would have precluded normal operation.