Steens Mountain Wilderness, Federal wilderness area in southeastern Oregon, United States.

Steens Mountain Wilderness is a protected area in southeastern Oregon that features dramatic eastern cliffs dropping steeply and gentler slopes descending westward. The terrain includes canyons, ridges, and river valleys that support diverse plant and animal life across changing elevations.

Steens Mountain rose about 20 million years ago when pressure beneath the Earth thrust up the block, creating the steep eastern face and gentler western slope. Ice Age glaciers later cut deep gorges and left depressions now filled by Lily, Fish and Wildhorse lakes. The Steens Mountain Wilderness, within the Steens Mountain Cooperative Management and Protection Area, covers 170,166 acres, of which 98,859 acres are closed to grazing.

The wilderness lies within the Steens Mountain Cooperative Management and Protection Area, run by the Bureau of Land Management. Of its 170,166 acres, 98,859 are closed to grazing and free of cattle, while herds of Kiger mustangs roam elsewhere in the reserve. Visitors can watch bighorn sheep, pronghorn and sage grouse across the elevation zones.

The wilderness lies within the Steens Mountain Cooperative Management and Protection Area, managed by the Bureau of Land Management. Elevations run from 4,200 feet in the Alvord Desert sagebrush to 9,733 feet at the summit, so snow can linger high up while the desert floor stays open. Cattle are excluded from 98,859 acres on top of the mountain, but grazing occurs elsewhere in the wilderness.

Steens Mountain rose about 20 million years ago when pressure beneath the surface thrust a single fault block upward, giving the mountain its steep eastern face and gentler western slope. Ice Age glaciers later cut deep gorges into the peak and left depressions that now hold Lily, Fish and Wildhorse lakes.