On August 13, 2000, at 1330 mountain daylight time, a Cessna 310D, N6981T, sustained substantial damage during a landing gear retracted landing at Front Range Airport, Watkins, Colorado. The private pilot and sole occupant was not injured. The flight was operating under Title 14 CFR Part 91 and no flight plan was filed. Visual meteorological conditions for this cross-country flight that originated in Granby, Colorado, approximately 2 hours prior to the accident. According to the pilot, he was distracted by an abnormal descent given by Air Traffic Control, and another aircraft waiting for takeoff and he forgot to lower the landing gear. He said he heard an oral warning device just prior to touch down and thought it was the stall warning. According to a repair station that assessed the damage, the belly skins and some ribs and stringers sustained damage.