The Black Canyon of the Gunnison was formed when the Gunnison uplift raised much of this area of Colorado. The hard rocks trapped the Gunnison River forcing it to slowly cut into the rock gradually forming the Black Canyon. The hard erosion resistant rock formed a very narrow step sided canyon stretching for 53 miles. Now the National Park is made up of the deepest most scenic 14 miles of the canyon. Upstream are three dams. They have filled the canyon upstream forming the Blue Mesa Reservoir, largest man made lake in Colorado. These dams have tamed the Gunnison somewhat.
The photograph on the top left shows the Gunnsion River flowing through the Black Canyon of the Gunnison. No other canyon in the United States combines all three elements of narrow, steep and deep the way the Black Canyon does.
The photgraph on the bottom left shows lighter colored pegmatite rock forming vetical ribbons of stone in the darker gneiss. This happened millions of years ago when the pegmatite was molten and it forced itself into small cracks in the other formation. When it was in the cracks it hardened.
