Abstract: Employee #1, who worked for a state agency that did manual conservation work, was helping to re-route a trail for the Forest Service. He was standing on the trail talking to a coworker when a large rock weighing approximately 100 lb came loose and rolled down the hill. It struck Employee #1's forearm and caused him to fall backward approximately 15 ft. He was taken to Sutter Coast Hospital, where he was treated and released. He was still experiencing pain the next day, and he returned to the hospital, where surgery was performed on his forearm muscle. The cause of the accident is not known. It had rained heavily shortly before, but no other reason could be identified for the boulder to roll downhill.