On September 4, 1996, about 0745 mountain daylight time, N2595N, a Cessna 120, operated by the Nampa Taildraggers Flying Club, Nampa, Idaho, groundlooped during landing in Nampa and was substantially damaged. The student pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed and no flight plan had been filed. The local instructional flight was conducted under 14 CFR 91. According to an eyewitness (statement attached): "[The] aircraft touched down and started porpoising. It looked like he was about to get the aircraft under control, but then it turned left and groundlooped off the left side of the runway." According to an FAA aviation safety inspector from Boise, Idaho, the student pilot lost directional control during landing, swerved off the runway, and collided with rough terrain. No preimpact mechanical malfunctions were reported by the pilot or the inspector. The student pilot had accumulated a total of 48 hours of flying time in the Cessna 120. Calm wind conditions were reported at the time of the accident.