Fort Huachuca began in 1877 as Camp Huachuca, established in this area because of its sheltering hills and perennial stream, and in 1882 it became Fort Huachuca, whose soldiers protected settlers and transportation routes during the Apache Indian Wars. The fort remained active through World War I and was home to the 10th Cavalry Regiment, one of the original all African-American cavalry regiments. During World War II, on September 9, 1943, the federal government leased 3,220 acres from the Boquillas Land and Cattle Company for the fort's East Artillery Range, where the land was used for artillery and infantry training. Part of the leased land included the ruins of Charleston, a town founded in 1879 and abandoned before 1889, and the U.S. Army improved the ruins so infantry troops could practice simulated village and street fighting in an urban-like setting. Between 1946 and 1947, leases affecting the Boquillas land and Charleston ruins were terminated or cancelled, and in the summer of 1947 Fort Huachuca closed. That year, Detachment No. 14 of the 9800th Technical Support Unit searched the Boquillas Area of Cochise County for ordnance and explosive hazards, though historical documentation does not provide specific locations where items were found or areas cleared. In 1951, the Army returned to the developed area of the fort and began a major renovation of the post. On November 18, 1988, the U.S. Department of Interior, Bureau of Land Management established 56,000 acres along the San Pedro River, including the Boquillas land, as the San Pedro Riparian National Conservation Area. On September 30, 1999, the U.S. Army Corps of Engineers determined that the Boquillas land and the former Charleston ruins were eligible for the Formerly Used Defense Sites Program; this property encompasses 3,220 acres within the conservation area, bordered by the active fort on the west and the San Pedro River on the east. Munitions related to past military use have been reported in the conservation area, and potentially hazardous military debris could remain.