On March 20, 2001, at approximately 1115 mountain standard time, a Cessna 340, N9940F, was substantially damaged when it collided with a bird while on approach to San Luis Valley Regional Airport, Alamosa, Colorado. The private pilot and his five passengers were not injured. Visual meteorological conditions prevailed. An instrument flight rules flight plan was filed for this business flight being conducted under Title 14 CFR Part 91. The flight departed Cedar City, Utah, at approximately 0730. According to the pilot's statement, he had just passed over the airport at 9500 feet mean sea level and entered the downwind leg for the approach to runway 20. At that moment he encountered a flock of large birds that flew up from below. One bird struck the leading edge of the right wing at approximately 3 feet inboard of the tip tank. The plot declared an emergency and landed without further incident. The airplane sustained substantial damage to the right wing's leading edge, skin, wing spar and auxiliary fuel cells. At the time of the accident, winds were light and variable at 3 knots. The bird that was fatally injured was later identified as an adult sand hill crane.