Camp Grant Rifle Range in New Milford, just south of Rockford, served as a U.S. Army training camp during World War I for small arms, thirty-seven-millimeter infantry gun, mortar, and anti-aircraft gun use, and during World War II it was used by the National Guard and trained medical corps. It once housed 50,000 infantry men and had a hospital for 1,500 patients. In the 1950s, the camp was declared surplus, and the Rockford Park District acquired 312 acres of the property, which is now Atwood Park and Education Center with a lodge, campground, outdoor education center, picnic areas, shelters, and a boat ramp. Because troops practiced with many kinds of ordnance, the site included practice artillery rounds such as thirty-seven-millimeter projectiles and three-inch Stokes mortar shells, while World War II target practice included point thirty and point forty-five caliber firearms munitions, Stokes trench mortar, thirty-seven-millimeter and three-inch anti-aircraft artillery, and hand grenades. Like many Military Munitions Formerly Used Defense Sites across the United States, the property retained remnants of military use, including munitions and ordnance left on the land and in the water, and soldiers training there fired practice rounds into the Kishwaukee River. Since the 1980s, the U.S. Army Corps of Engineers has investigated and cleaned up such sites; in 1995 it scoured the former Camp Grant Rifle Range and found 1,200 pieces of ordnance, none containing high explosives, and from April through June 2004 the north end of the former range and Blackhawk Valley Campground was swept and any ordnance found was detonated in place. Because old munitions may still be live and deadly, people are warned not to pick up, touch, move, or kick any shells or ordnance found there and to follow the three Rs: recognize the danger, retreat, and report it immediately.