Leon Springs Military Reservation is twenty miles northwest of San Antonio in the northwestern section of Bexar County. It is readily accessible from Interstate Highway 10, Harry Wurzbach Road, and Blanco Road. As the Indian wars wound down in the late 1800s, the United States Army began consolidation of the many small posts on the western frontier. In 1882 the Post at San Antonio (now Fort Sam Houston) was selected to be one of the larger garrison sites. Expansion meant a need for more and larger training areas, including large maneuver areas and ranges for the practice firing of small arms and artillery. Short-term arrangements for training areas near Kerrville and Leon Springs were made, while an extensive search for more permanent range facilities was begun as early as 1890. The Post at San Antonio was renamed Fort Sam Houston in 1890, still without an adequate firing range. The Spanish-American War resulted in the further expansion of the fort to brigade status and the beginning of a construction program that made the fort the largest army post in the United States. In 1906 and 1907, 17,273 acres near Leon Springs was acquired, and the Leon Springs Military Reservation was established. In 1908 the first military maneuvers were held involving both regular army and national guard units. These training exercises included units of the Third Cavalry, First Field Artillery, and Ninth and Nineteenth infantries, as well as signal and hospital units. The first recorded artillery firing at the reservation occurred on April 27, 1909. The first use of aircraft took place on March 17, 1911, when Benjamin Foulois and Phillip O. Parmalee delivered a message from Fort Sam Houston to the reservation. Events beginning in 1916, when Francisco (Pancho) Villa crossed the United States border, and extending on into 1917 and World War I, greatly accelerated the build-up of facilities at both Fort Sam Houston and at Leon Springs.
In February 1917 Maj. Gen. Frederick Funston, commanding general of the Southern District, died in San Antonio, and facilities at the Leon Springs Reservation were named Camp Funston in his honor. Another camp in Kansas was also named Funston, and since Funston was a native of Kansas, the Leon Springs Camp was redesignated Camp Stanley, after Brig. Gen. David S. Stanley, former commander of the Department of Texas. On May 8, 1917, the First Officers Training Camp was established just north of Anderson Hill at Camp Funston. The purpose of the FOTC was to provide in ninety days most of the junior officers for newly formed divisions. The trainees became known as "ninety-day wonders." In July 1917 the Fifty-seventh Infantry moved to Camp Funston with Lt. Dwight D. Eisenhower. Lt. Walton H. Walker, who later commanded the United States Eighth Army in Korea, was also a member of the Fifty-seventh at Camp Funston. In the spring of 1917 a remount station was established at Leon Springs to process and maintain horses used by the mounted arms of the military services.
In September 1917 an additional 16,000 acres of land was leased, extending the Leon Springs Military Reservation to the south. A new camp was established there and named in honor of Brig. Gen. John L. Bullis, who as a lieutenant had commanded the Black Seminole scouts during the Indian wars. By the end of the World War I more than 32,000 acres near Leon Springs was in use by the army. A total of $1,350,000 had been spent on construction of cantonments at Camp Stanley and Camp Bullis. Between World War I and World War II improvements continued to be made. The old San Antonio Arsenal, originally built in 1859, was poorly located and by 1919 had been surrounded by the downtown area. It was moved to Camp Stanley and by 1937 required an area of 1,760 acres. At this time Camp Stanley was devoted to storage and testing of ordnance materials, and all other military activities at the Leon Springs Military Reservation were conducted at Camp Bullis. In 1990 the Leon Springs Military Reservation consisted of Camp Stanley, largely used for ammunition storage and testing, and Camp Bullis, utilized for firing ranges, maneuver areas for army, air force, and marine combat units, and for field training of the various medical units from Brooke Army Medical Center at Fort Sam Houston. The total area was slightly more than 26,000 acres.