Fort Knox is a United States Army post in Kentucky south of Louisville and north of Elizabethtown. It is also the site of the United States Bullion Depository, which is used to house a large portion of the United States' official gold reserves. The 109,000 acre (170 sq mi, 441 km²) base covers parts of Bullitt, Hardin, and Meade counties. It currently holds the Army Human Resources Center of Excellence to include the Army Human Resources Command, United States Army Cadet Command and the United States Army Accessions Command. For 60 years, Fort Knox was the home of the U.S. Army Armor Center and the U.S. Army Armor School (now moved to Fort Benning), and was used by both the Army and the Marine Corps to train crews on the M1 Abrams main battle tank. The history of the U.S. Army's Cavalry and Armored forces, and of General George S. Patton's career, can be found at the General George Patton Museum on the grounds of Fort Knox.