SRER was originally contained within the Santa Rita Forest Reserve, as established by Presidential Executive Order of April 11, 1902 by President Theodore Roosevelt. President Mckinley also signed an Executive Order in on October 10, 1900 setting aside sections 26, 27, 34 and 35 in T.14S., R.14E, which were included in 1902 transfer. During this time, forest reserves were administered by the Department of the Interior. In 1905, the forest reserves were transferred to the Department of Agriculture and consolidated with the Bureau of Forestry to form the Forest Service. In 1901, Dr. David Griffiths of the Bureau of Plant Industry and Dr. R. H. Forbes and Dr. J. J. Thornber, with the Agriculture Experiment Station at the University of Arizona in Tucson, began making observations and some investigations on SRER and at the Arizona Experiment Station (Griffiths 1904). In 1903, the Carnegie Institute of Washington established the Desert Laboratory at Tucson for continued work in studies of desert plants and range investigations.
On July 2, 1908, Executive Order 908 consolidated the Dragoon, Santa Catalina, and Santa Rita National Forests to establish the Coronado National Forest. On July 1, 1910, Executive Order 1222 transfered lands then known as the Santa Rita Range Reserve to the Bureau of Plant Industry, which was subsequently transfered to the Forest Service, Branch of Research, in 1915. Henceforth, SRER was administered as a Forest Service research area with no national forest system designation. On July 1, 1910, President Taft set aside 41,911.76 acres, which consisted of most of the present size of SRER. Two other Executive Orders (4261 of July 3, 1925, and 4602 of March 2, 1927) provided for the addition of 12,120 acres. These latter Orders were revoked by Public Land Order No. 1363, November 15, 1956. But, an addition of about 711 acres, formerly described in the Secretary of Agriculture's Regulation "U-4" of January 15, 1941, included the site occupied by the experimental range headquarters, resulting in the present size of 53,159 acres.
The Forest Service Southwestern Station's headquarters remained in Tucson until 1953, when it was consolidated with the Rocky Mountain Station. The Southwestern Station remained active until 1975, when the field unit was consolidated with the Experiment Station at Tempe.