On July 5, 2003, approximately 1030 mountain daylight time, a Cessna T210M, N761QN, registered to Corpat, Inc., and being flown by a private pilot, sustained substantial damage to the right horizontal stabilizer leading edge when the aircraft struck a deer during an aborted landing at Schafer USFS airstrip, approximately 19 nautical miles east-southeast of Essex, Montana. The pilot and three passengers were uninjured. Visual meteorological conditions prevailed and no flight plan had been filed. The flight, which was personal, was operated under 14CFR91, and originated from Seeley Lake, Montana, approximately 1000. The pilot reported that after overflying the mountain airstrip and observing no objects/wildlife on the runway he commenced an approach to runway 25, a 3200-foot long turf strip with a downhill slope. The pilot stated "...As we approached the landing on final the runway was clear and I did not see any hazards including animals on or near the runway. Although landing a little long it appeared to be very manageable..." (refer to attached NTSB Form 6120.1). After touchdown, and while rolling at 45 knots, he observed a deer enter the runway environment from the right. He reported that he was concerned that the deer would cross in front of the aircraft before the aircraft's speed could be adequately reduced, and that he then applied full power and aborted the landing pulling the nose up to a slightly higher than usual nose up attitude. The occupants felt a "thump" and the pilot continued the climb out leaving the gear extended. After ascertaining the controllability of the aircraft and noting the damage to the leading edge of the right horizontal stabilizer, he then diverted to Missoula. The Schafer USFS airstrip is an unfenced, uncontrolled. and unmanned public airstrip. The Airport Master Record (FAA Form 5010-1), whose last inspection date was recorded as November 6, 1996, contained a remark stating: "Watch for horses or big game animals on r[unwa]y" (refer to attachment 5010-I).