On June 30, 2000, approximately 0850 mountain daylight time, a Cessna 172N, N4642J, operated by Gregg Flying Service, Inc., was substantially damaged when it collided with terrain during landing at Animas Air Park, Durango, Colorado. The student pilot, the sole occupant aboard, was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the instructional flight being conducted under Title 14 CFR Part 91. The flight originated at Durango a few minutes before the accident. According to the pilot's accident report, his instructor told him to make a touch-and-go landing on runway 1. The takeoff and landing approach were uneventful. He said he deployed 20 degrees of flaps and slowed the airplane to about 65 knots. As he approached the runway threshold, he closed the throttle and raised the nose. The airplane "started to go up and down too rapidly." The main landing gear "hit hard" and the airplane "bounced off the ground and . . .started to torque to the left. The [air]plane then landed on its [nose] gear and skidded left off the runway," coming to rest against a barbed wire fence. Damage was thought to be minimal until repairs were begun. The left horizontal stabilizer was damaged and the firewall was buckled.