On June 6, 1994, approximately 2145 mountain daylight time (MDT), a Rockwell International AC-690, N265JH, impacted deer during the landing roll at Natrona County Airport, Casper, Wyoming. The airline transport rated pilot and his passenger were not injured, but the aircraft sustained substantial damage. The FAR Part 91 business flight, which departed Jackson Hole Airport, Jackson, Wyoming, about 2045 MDT, was being operated in visual meteorological conditions at the time of the accident. The aircraft had been on an IFR flight plan, and there was no report of an ELT activation. According to the pilot, the aircraft was decelerating through about 80 knots when two or more deer ran onto the runway, and were impacted by the nose and right wing of the aircraft. The pilot said that the deer were not illuminated by the landing light until the moment of impact.