Mount Forgotten, Mountain summit in the North Cascades, Snohomish County, Washington, United States

Mount Forgotten is a 6,005-foot (1,830 m) summit near the western edge of the North Cascades in Snohomish County, Washington, on Mount Baker-Snoqualmie National Forest land. It rises five miles north of Barlow Pass along the Mountain Loop Highway near Monte Cristo, and its runoff drains into tributaries of the Sauk River.

Mount Forgotten is composed of volcanic breccia, and its formation belongs to the long volcanic history of the North Cascades, which dates back to the late Eocene Epoch. About 50 million years ago, small fragments of oceanic and continental lithosphere called terranes created the North Cascades. During the Pleistocene, repeated glaciation scoured the landscape, leaving rock debris and shaping the U-shaped river valleys below the summit.

The name Mount Forgotten is not explained in the sources, and no named trail to the summit is documented there. The peak stands on Mount Baker-Snoqualmie National Forest land five miles north of Barlow Pass, above the Sauk River tributaries that drain its slopes. Its volcanic breccia, formed in the North Cascades about 50 million years ago, is the rock a climber meets on the mountain.

The summit lies five miles north of Barlow Pass along the Mountain Loop Highway, near Monte Cristo, on Mount Baker-Snoqualmie National Forest land. July through September gives the most favorable weather for climbing. Snow on the west side is wet and heavy, so avalanche danger is high in winter.

Mount Forgotten is composed of volcanic breccia, and Glacier Peak, a stratovolcano that began forming in the mid-Pleistocene, lies 15.35 mi (24.70 km) to the east. The nearest higher peak is Mount Pugh, 4.22 mi (6.79 km) to the northeast, and runoff from the mountain drains into tributaries of the Sauk River.