Jefferson Proving Ground, Indiana

A former major firing range and weapons test site in southern Indiana. Since 1941, 23 million test rounds have been fired here, with an estimated 1.5 million unexploded devices, including armor-piercing uranium-tipped rounds, left strewn about the site. Some have penetrated as deep as 24 feet into the earth. The northern area where the ranges are, is around 15 miles long, and 5 miles wide. There were 268 gun positions in the north area, which were used to test munitions until 1994. A firing line divided the north area from the cantonment area at the southern end. In 1995, the base was closed as ordained by the Base Closure and Realignment Act (BRAC) of 1988, resulting in some of the site's former operations being relocated to the U.S. Army Yuma Proving Ground in Arizona. The 55,000 acre site has over 300 buildings. Both the Air National Guard and the U.S. Air Force continue to use the bombing range and the firing range respectively. In 2000, the Big Oaks National Wildlife Refuge was established as an overlay refuge, as portions of the firing range contain significant wildlife habitats.