Fort Huachuca is a United States Army installation, established on 3 March 1877 as Camp Huachuca. The garrison is now under the command of the United States Army Installation Management Command. It is in Cochise County, in southeast Arizona, approximately 15 miles north of the border with Mexico and at the northern end of the Huachuca Mountains, adjacent to the town of Sierra Vista. From 1913 to 1933, the fort was the base for the "Buffalo Soldiers" of the 10th Cavalry Regiment. During the build-up of World War II, the fort had quarters for more than 25,000 male soldiers and hundreds of WACs. In the 2010 census, Fort Huachuca had a population of about 6,500 active duty soldiers, 7,400 military family members, and 5,000 civilian employees. Fort Huachuca has over 18,000 people on post during the peak working hours of 07:00 and 16:00 on weekdays.
The major tenant units are the United States Army Network Enterprise Technology Command and the United States Army Intelligence Center. Libby Army Airfield is on post and shares its runway with Sierra Vista Municipal Airport. It was an alternate landing location for the space shuttle, but it has never been used as such.