The Tatoosh Wilderness, located in Washington, in the Pacific Northwest region of the United States, is managed by the U.S. Forest Service and protects 15,750 acres (64 km2). In 1984 it was officially designated as wilderness by Congress. The Tatoosh Wilderness, a part of Gifford Pinchot National Forest, is a scenic alpine environment that complements the adjacent Mount Rainier National Park. It features Tatoosh Peak, a member of the Tatoosh Range. Its addition to the wilderness system will protect and preserve its natural beauty.
Tatoosh means "breast" in the Chinook Jargon, in reference to the two large rock outcrops on the south face of Butter Peak. In 1932, a fire Lookout was built. Martha Hardy later wrote about her experiences keeping watch at the fire lookout in her 1947 book Tatoosh (ISBN 0-89886-005-9).
The Tatoosh Wilderness is accessible from the north from Mt. Rainier National Park and from the south via the Tatoosh Lakes trail. A spur of the Tatoosh Lakes trail extends to the location of the fire lookout that Martha Hardy wrote about, although only the foundations of the lookout building remain.