National Forests in Oregon Maps, 1910-1989

Prior to the establishment of individual National Forests, the state of Oregon had several forest reserves that had been formed in 1891-1893. The largest reserve, Cascade Range Forest Reserve, was established in 1891. In 1905 the forest reserves were transferred to the management of the Department of Agriculture, who then formed the United States Forest Service to manage these National Forests.

Despite petitions by local citizens to dissolve the Forest Reserves, the Reserves persisted until 1908, when they were split up into several National Forests. Many were just renamed from a reserve to National Forest. However, the 4.5-million-acre Cascade Range Forest Reserve was divided into the Oregon, Cascade, Umpqua, and Crater National Forests. Some of the forests were further divided through the 1930s so that the portions of the Oregon and Cascade National Forests west of the crest of the Cascades were split and renamed into the Mt. Hood and Willamette National Forests. Areas to the east were divided into the Deschutes and Paulina National Forests. While some of the above forests have maintained their original National Forest names, many have been renamed and combined since they were initially formed.

The National Wilderness Preservation System was established by the Wilderness Act in 1964. Within Wilderness Areas, human activities are limited to scientific study and non-mechanized recreation. Areas within the National Forests that were already designated as "wilderness" or "wild" became part of the system in 1964; in Oregon, this included the Diamond Peak, Eagle Cap, Kalmiopsis, Mount Hood, Mount Washington, Strawberry Mountain, and Three Sisters Wilderness Areas. The Mount Jefferson Wilderness Area was established in 1968.