Pinal Mountains National Forest was established as the Pinal Mountains Forest Reserve by the U.S. Forest Service in Arizona on March 20, 1905 with 45760acres. It became a National Forest on March 4, 1907 and encompassed the entirety of the Pinal Mountains south of Globe, Arizona and some areas surrounding the mountains. On January 13, 1908 the forest was combined with Tonto National Forest and the name was discontinued.