On May 11, 2001, about 1825 mountain daylight time, a Cessna 182P, N8188G, sustained substantial damage during the landing roll at Lemhi County Airport, Salmon, Idaho. The airplane is owned and operated by the pilot, and was being operated as a visual flight rules (VFR) personal/pleasure flight under Title 14, CFR Part 91, when the accident occurred. The private pilot, the sole occupant of the airplane, was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight. The flight originated from Salmon approximately one hour prior to the accident. During a telephone interview with the National Transportation Safety Board on May 14, the pilot stated that the airplane touched down on the centerline of runway 17. He reported that shortly after touchdown, the airplane began to drift right of centerline. He stated that he applied corrective actions in an effort to correct the situation, however, the airplane departed the right side of the runway. After departing the right side of the runway, the airplane encountered soft, muddy terrain and nosed over. The airplane sustained substantial damage to the fuselage and right wing. No mechanical failures were reported.