On July 13, 1998, at 1600 hours Pacific daylight time, a Schemp-Hirth Discus A glider, N95KM, lost lift and impacted terrain approximately 10 miles northeast of Bridgeport, California. The aircraft was destroyed, and the private pilot, the sole occupant, was not injured. The personal flight originated at the Minden, Nevada, airport at 1356, and was en route to the Lone Pine, California, airport. Visual meteorological conditions prevailed and no flight plan was filed. The pilot reported that she was flying low in a canyon with no thermal activity. She attempted to gain lift by flying close to the ridge. The glider impacted a tree and the wings were torn off. The pilot reported that the glider then spun into the canyon wall and impacted the terrain. The elevation at the accident site was approximately 7,700 feet msl. The pilot reported that she had not experienced any mechanical malfunction with the aircraft prior to the accident.