Lost Creek Wilderness, Protected wilderness area in Pike National Forest, Colorado

Lost Creek Wilderness covers 119,790 acres of Pike National Forest in Jefferson and Park counties, south of Bailey. Its two low foothill ranges, the Kenosha and Tarryall Mountains, hold rounded granite domes and knobs, natural arches, and narrow gorges lined with pinnacles and spires. Bison Peak, at 12,431 feet, is the highest point. Green shrubs and small trees grow between the reddish-brown rock lobes, and forested slopes rise toward a broad ridge.

The Lost Creek Scenic Area, a 16,798-acre tract within the wilderness, was created in 1963 under the 1939 U-Regulations, a precursor of the Wilderness Act. It was designated a National Natural Landmark in 1966. The surrounding Lost Creek Wilderness is managed by the U.S. Forest Service.

The name comes from Lost Creek, a perennial stream that vanishes and resurfaces before joining Goose Creek, which drains into the South Platte River at Cheesman Reservoir east of the wilderness. Lost Park, as the area is also called, was one of the last refuges of the American bison in the United States. Episode 2 of Season 1 of the television series Supernatural is set in the wilderness, at the fictitious Blackwater Ridge.

The wilderness holds 130 miles (210 km) of trails, and a section of the Colorado Trail crosses Lost Creek before running along the northeast boundary toward Kenosha Pass. The area lies south of Bailey, entirely inside Pike National Forest, and is managed by the U.S. Forest Service. Its closeness to Denver makes it busy in both summer and winter, when snowshoeing, cross-country skiing and winter camping join hiking and rock climbing.

Lost Creek vanishes and resurfaces at least nine times in the Lost Creek Scenic Area, a 16,798-acre National Natural Landmark within the wilderness that was designated in 1966. The stream finally joins Goose Creek, which reaches the South Platte River at Cheesman Reservoir east of the wilderness.