It was established by the United States Congress in 1964 and is named for the Three Sisters volcanoes.

[7] Many types of landforms make up the wilderness area, but the most common are volcanic features, the most notable being the Cascades which are stratovolcanoes having formed around 1.6 million years ago.

Including Broken Top—just to the south at 9,175 feet (2,797 m) — there are 14 glaciers offering one of the best examples of the effects of glaciation in the Pacific Northwest.

[12] Popular recreational activities in the Three Sisters Wilderness include camping, hiking, climbing and fishing.

[12] The 9.8-mile (15.8 km) French Pete Trail and its surrounding old-growth forest, a nationwide political issue in the 1970s, are located on the western edge of the wilderness near Cougar Reservoir.