Mount Hood National Forest was first established as the Bull Run Forest Reserve in 1892. It was expanded in 1893. It was merged with part of Cascade National Forest on July 1, 1908 and named Oregon National Forest with . It extended from the Columbia River to the South Fork of the Santiam River until 1911 when the Santiam National Forest was proclaimed and the southern border of the Oregon National Forest was moved north to the divide between the Santiam River and Clackamas River. The name was changed again to Mount Hood National Forest in 1924.