Sierra Madre National Forest was established as the Sierra Madre Forest Reserve by the U.S. Forest Service in Wyoming on November 5, 1906 with 370,911 acres (1,501.02 km2). It became a National Forest on March 4, 1907. On July 1, 1908 the entire forest was combined with Park Range National Forest to create Hayden National Forest and the name was discontinued. [1]