fish hatchery and Spotted Eagle Recreation Area. Approximately 1,800 acres are under irrigation in the Yellowstone River Valley west of the Laboratory headquarters. About 625 acres are in cultivated crops and 1150 in irrigated pastures. The remainder of the laboratory is rough, broken badlands typical of range cattle producing areas of the Northern Great Plains. In 1954 the United States Air Force opened the 902nd Aircraft Control and Warning station on the reservation about two miles south of the Yellowstone River and ten miles west of Miles City. This station was part of the Cold War air defense system protecting the United States in case of war with the Soviet Union. The station operated until 1968 when it was closed because of the advance of electronics in radar detection. At any given time there were in the neighborhood of 100 to 125 airmen and officers stationed at this location. The Range Riders Museum, located on the original Fort Keogh cantonment in nearby Miles City, Montana, offers historical exhibits of the fort's days as Milestown. Giant snowflake Guinness World Records reports that the largest natural snowflake ever recorded, measuring in diameter, fell at Fort Keogh on January 28, 1887. Gallery See also List of military installations in Montana Notes References Further reading Barnes, Jeff. (2008). Forts of the Northern Plains: Guide to Historic Military Posts of the Plains Indian Wars. Mechanicsburg, PA: Stackpole Books. External links Fort Keogh Collection, University of Montana Archives Fort Keogh History links, USDA webpage Historical photos of Fort Keogh Bibliography of books and articles on Fort Keogh "USDA Livestock and Range Research Laboratory", official webpage of the Agricultural Research Service History of Montana Keogh 1876 establishments in Montana Territory Keogh National Register of Historic Places in Custer County, Montana