Black Canyon of The Gunnison National Park - Geology

Geology

The Gunnison River drops an average of 34 feet per mile (5 m/km) through the entire canyon, making the 5th steepest mountain descents in North America. In comparison, the Colorado River through the Grand Canyon drops an average of 7.5 feet per mile (1.4 m/km). The greatest descent of the Gunnison River occurs in the park at Chasm View dropping 240 feet per mile (45 m/km). The Black Canyon is so named on account of its steepness which makes it difficult for sunlight to penetrate very far down the canyon. As a result, the canyon walls are most often in shadow, causing the rocky walls to appear black. At its narrowest point the canyon is only 40 feet (12 m) across at the river.

The extreme steepness and depth of the Black Canyon formed as the result of several geologic processes acting together. The Gunnison River is primarily responsible for carving the canyon, though several other geologic events had to occur in order to form the canyon as it is seen today.

• Overview Black Canyon with Gunnison River

• Satellite image of the park and Curecanti National Recreation Area