The Wenaha–Tucannon Wilderness is a federally designated wilderness area in the Blue Mountains of northeastern Oregon and southeastern Washington, created in 1978 and spanning 177,423 acres in the Umatilla National Forest. Its rugged basalt ridges and deep canyons rise from about 2,000 feet along the Wenaha River to 6,401 feet at Oregon Butte. Water drains toward several river systems, and plant communities shift with elevation from ponderosa pine in lower drainages to lodgepole pine, larch, fir, spruce, and subalpine vegetation higher up. The area supports moose, elk, bighorn sheep, black bear, cougar, grey wolf, and salmon and steelhead habitat, and includes about 200 miles of trails for outdoor recreation.