The Black Canyon of the Gunnison River is one of Colorado's—and indeed the West's—most awe-inspiring places. A vivid testament to the powers of erosion, the canyon is roughly 2,000 feet deep. At its narrowest point, it spans 1,000 feet at the rim and only 40 feet at the bottom. The steep angles of the cliffs make it difficult for sunlight to fully break through during much of the day, and ever-present shadows blanket the canyon walls, leaving some places in almost perpetual darkness. No wonder it's called the "Black Canyon."