On May 10, 2003, at 1015 mountain daylight time, a Cessna P210N, N711BG, sustained substantial damage during a gear up landing on runway 10R at the Boise Air Terminal/Gowen Field, Boise, Idaho. The airplane was registered to and operated by a private individual. The certificated commercial pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed for the personal flight, and a flight plan was not filed. The flight, which was operating under the provisions of 14 CFR Part 91, departed Boise at 0940. According to the Pilot/Operator Accident Report (NTSB form 6120.1/2), the pilot reported that he had made two practice instrument approaches, and "at the last minute on the second approach I was cleared for a touch-and-go. The best way I can describe it, I was still in an 'instrument approach mindset' and failed to lower the gear." The pilot stated that he landed gear up on runway 10R and skidded to a stop. There was no post-crash fire. In a telephone interview with the NTSB investigator-in-charge, when asked if he had heard the landing gear warning horn prior to contacting the runway, the pilot replied, "I didn't even know there was one." The pilot also stated he did not perform the Before Landing checklist. An FAA inspector, who surveyed the aircraft damage, reported substantial damage to three stringers on the underside of the airplane, as well as skin damage to the belly of the airplane. The inspector also confirmed that upon further examination of the aircraft, the landing gear warning horn worked properly when tested.