Located in the Umatilla National Forest in Oregon.

The Wenaha-Tucannon Wilderness was created by the Endangered American Wilderness Act of 1978. The wilderness is located in the northern Blue Mountains of southeastern Washington and northeastern Oregon and encompasses 177,465 acres.

The majority of the wilderness is characterized by rugged basaltic ridges and outcroppings separated by deep canyons with steep side slopes. The Wenaha River, Crooked Creek, Rock Creek and Butte Creek have cut deep canyons into the tablelands and left heavily timbered areas along the bottoms. Elevations range from 2,000 feet on the Wild and Scenic Wenaha River to 6,401 feet at Oregon Butte. Plant communities vary widely from bunchgrass slopes to higher subalpine areas of lodgepole pine and subalpine fir.

Nearly every wildlife species present in the Blue Mountains can be found within the Wenaha-Tucannon Wilderness including Rocky Mountain elk and bighorn sheep, white-tail and mule deer, black bear, cougar, coyote, and pine martens. Both the Tucannon and Wenaha Rivers provide good spawning habitat for Chinook salmon and steelhead.

The managed trail System within the wilderness totals over 200 miles. Trails are managed to provide a primitive, unconfined recreation experience as well as access to various portions of the wilderness. Several developed campgrounds are located at or near major trail heads around the perimeter of the wilderness.

The primary recreation activity within the wilderness has traditionally been elk hunting with a large number of hunters packing into the wilderness on horseback each fall. Recently, however, there has been an increase in anglers and backpackers during the summer and early fall months. The area is very popular with horseback riders, and several trail heads are equipped to accommodate horses.

The normal hiking season is from June through November. Access to the wilderness can be gained in early spring along the Wenaha River near Troy, Oregon. Many higher elevation trail heads remain inaccessible through June Most trails descend sharply into the rugged river canyons of the Wenaha and Tucannon Rivers and their tributaries