On July 10, 2018, about 1832 Pacific daylight time, a Schempp Hirth DISCUS CS glider, N104TH, collided with terrain during a forced off airport landing, following a loss of lift, near Goldfield, Nevada. The commercial pilot sustained serious injuries. The glider sustained substantial damage to the fuselage and both wings. The glider was registered to Sparrowhawk21 LLC. and operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal local flight. Visual meteorological conditions existed about the time of the accident, and no flight plan had been filed. The flight originated from Tonopah Airport (TPH), Tonopah, Nevada about 1330. The pilot reported that during the long cross country flight, he had to deviate to an alternate airport, due to deteriorating weather. While attempting to reach his selected off airport landing site, he encountered continuous sinking air. He realized that he would not make it and made the choice to land on a nearby road. Just prior to the landing touchdown the right wing impacted a dirt berm that paralleled the road, which caused a ground loop. The glider cartwheeled and came to rest inverted. The pilot reported no mechanical malfunctions with the airframe that would have precluded normal operation.