Gearhart Mountain Wilderness, Wilderness area in Fremont-Winema National Forest, Oregon, United States

Gearhart Mountain Wilderness covers 22,823 acres in the Fremont-Winema National Forest, split between Lake and Klamath counties and entirely inside the Bly Ranger District. Its high mountain meadows, cirques and glacial valleys rise to Gearhart Mountain, the highest point at 8,364 feet (2,549 m). Small streams begin at the base of many cliffs and ridges.

The area was established as a Wild Area in 1943 and designated wilderness under the Wilderness Act of 1964. In 1984, 4,144 acres were added, bringing the total to 22,823 acres. The whole wilderness lies within the Bly Ranger District of the Fremont–Winema National Forest.

Gearhart Mountain honours James P. and William H. Gearhart, brothers who raised and traded cattle in the area from about 1873 to 1882. The name survives on the summit and the wilderness, while the old grazing ground is now a protected area where cattle no longer range.

The area includes roughly 20 miles of marked trails for hiking, with the main route running from south to north through varying terrain. Visitors should expect rugged mountain conditions, changeable weather, and minimal facilities since this is a wild, undeveloped landscape.

Gearhart Mountain's summit, at 8,364 feet the highest point in the wilderness, gives a view that reaches Steens Mountain to the east, the Cascade peaks to the west, Lassen Peak in California to the south and the Three Sisters to the north. The three main trails — Deming Creek, Lookout Rock and North Fork Sprague — converge just north of the summit.