On March 24, 1994, at 1645 mountain standard time, a Bellanca 8KCAB, N86807, veered off the runway during the landing roll at the Driggs Airport, Driggs, Idaho, and collided with a snow bank. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local instructional flight. The airplane was substantially damaged and the certificated flight instructor and private pilot were not injured. The flight instructor reported that the purpose of the flight was to give the private pilot instruction in the tailwheel airplane for sign off purposes. The private pilot performed two touch- and-go landings without incident. After the second takeoff, the flight instructor took over to demonstrate a landing to the private pilot. After the airplane touched down, the airplane veered slightly to the left. The flight instructor corrected with right rudder and right brake. The airplane swerved back to the right, however, the flight instructor again had to correct with left rudder. The swerving action continued until the pilot was unable to maintain directional control and the airplane veered sharply to the left and collided with a snow bank near the edge of the runway.