Camp Hale was established in 1942 in west-central Colorado to provide winter and mountain warfare training during World War II. The site was acquired by purchase from private owners and by use permits from the U.S. Department of Agriculture, Forest Service. The living area (cantonment area) for Camp Hale was constructed in Eagle Park, east of Highway 24 between Leadville and Red Cliff, Colorado. The camp was established here because of the natural setting of a large, flat valley bottom, surrounded by steep hillsides suitable for training in skiing, rock climbing and cold weather survival skills. The size of Camp Hale varied between 5,000 and 247,243 acres when it was an active military installation.

From 1942 to 1965, Camp Hale was used to train the 10th Mountain Division, the 38th Regimental Combat Team, the 99th Infantry Battalion and soldiers from Fort Carson in mountain and winter warfare. The Army also tested a variety of weapons and equipment at the site. From 1959 through 1965, the Central Intelligence Agency (CIA) secretly trained Tibetan soldiers at the installation. In July 1965, Camp Hale was deactivated and the Army returned control of the lands to the Forest Service in 1966.

Camp Hale was used as a military training site from 1942 to 1965. Both practice and live munitions were used in training. These munitions could still be present anywhere within the Camp Hale project area.

While munition training exercises were conducted throughout the Camp Hale area, one area of known heavy use was the East Fork valley. The East Fork valley is near the cantonment area of Camp Hale off U.S. Highway 24 and is located along the East Fork of the Eagle River. According to historical records, the valley was a major combat training area throughout the life of Camp Hale. The following munitions have been confirmed to have been used in the valley: anti-tank rockets, recoilless rifles, rifle grenades, hand grenades, high explosive and illumination mortars, artillery, practice antitank land mines, and small arms. Other munitions may also have been used in the valley. Records show that the CIA also used the valley for military training.