Diamond Mountain National Forest Wikipedia
Diamond Mountain National Forest was established as the Diamond Mountain Forest Reserve by the U.S. Forest Service in California on July 14, 1905 with 626,724 acres (2,536.26 km2). It became a National Forest on March 4, 1907. On July 1, 1908 a portion of Diamond Mountain was transferred to Plumas National Forest and the remainder to Lassen National Forest. The name was discontinued.