On January 30, 1998, approximately 1838 mountain standard time, a Cessna 180, N180AJ, sustained substantial damage when it nosed over during the landing roll at Friedman Memorial Airport, Hailey, Idaho. The commercial pilot, the sole occupant, was uninjured. The flight, which had originated at Magic Reservoir, was conducted under 14 CFR 91. Visual meteorological conditions prevailed at the time of the accident. There was no report of the ELT actuating. The pilot stated that he had landed at Magic Reservoir, a plowed runway with hard-packed snow and ice surface conditions. He believed that while taxiing for turnaround at the end of the runway, the right-hand brake apparently became hydraulically locked due to engagement of the parking brake mechanism on that side. He stated that at no time was the parking brake handle pulled. He said his takeoff on the icy runway seemed normal, and he was completely unaware of the locked condition of the brake at that time. Upon touchdown at Hailey, the airplane immediately veered violently to the right and the brake remained locked. The airplane swerved to the right before nosing over. Investigation determined that the parking brake locking lever on the right brake cylinder was in its overcenter position, locking the brake. The pilot reported that he never used the parking brake on this airplane.