MT. THIELSEN WILDERNESS
Umpqua National Forest
Box 1008
Roseburg, OR 97470
(541) 672-6601
Web site http://www.fs.fed.us/r6/umpqua/

Deschutes National Forest
1645 Highway 20 E.
Bend, OR 97701
(541) 388-2715
Web site www.fs.fed.us/r6/centraloregon/

Winema National Forest
2719 Dahlia
Klamath Falls, OR 97601
(541) 883-6714
Web site http://www.fs.fed.us/r6/winema/

Mt. Thielsen Wilderness lies along the crest of the Cascades east of Diamond Lake and south of Crescent Lake. Created by the 1984 Oregon Wilderness Act it is 55,100-acres in size. It is a Wilderness inside the Oregon Cascades Recreation Area which was created by Congress in 1984 to "manage, protect and enhance the recreation values".

Much of this Wilderness is made up of high alpine forests and open meadows. Elevations range from 5000 feet to the 9,182 foot summit of Mt. Thielsen. The Pacific National Scenic Trail (PCNST) winds through the Mt. Thielsen Wilderness for 26 miles along the summit of the Cascade Range.