[5][6] Much of the area sits above timberline at 12,000 feet (3,700 m) and it is recognized as one of the largest expanses of tundra in the contiguous United States.

The central, highest terrain of the wilderness is composed of basaltic lava flows of the Hinsdale Formation, which are dated at 16 to 19 million years old.

[8][9] Underlying these basalt flows are sheets of older volcanic rocks that are exposed around the periphery of the wilderness.

[8][6] Half of the Powderhorn Wilderness is above tree line and the alpine tundra here is dominated by grasses and forbs, though there are also extensive thickets of willow.

At lower elevations, particularly in the northern extension of the wilderness, montane forests occur and ponderosa pine is often dominate.

Other mammals include mountain lions, black bears, bobcats, coyotes, martens, marmots, and pikas.

These trailheads provide access to 45 miles (72 km) of interconnecting trails allowing multiple options for trips in the wilderness.

These two lakes are nestled in a beautiful glacial cirque, and the 4.8-mile (7.7 km) trip one-way is well worth the effort.