On September 5, 2007, about 0830 mountain daylight time, a Cessna 172M, N8945V, impacted terrain while maneuvering about 20 nautical miles north northeast of Thompson, Utah. The private pilot and the passenger received minor injuries, and the airplane sustained substantial damage. The airplane was being operated by the pilot as a 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed and no flight plan was filed. According to the pilot, he and the passenger were spotting for elk. He located some elk and maneuvered the airplane to put the elk on the passenger's side (right side) of the airplane. This resulted in the airplane flying up a box canyon. As the terrain rose, the pilot realized the airplane would not be able to climb over the ridge at the head of the canyon. He turned to the left and attempted to exit the canyon; however, the airplane impacted the terrain and nosed over.