Black Canyon of the Gunnison National Park, by Rose Houk

Black Canyon of the Gunnison National Park, by Rose Houk, Western national park Association, 2004.

Gunnison Canyon does not have a significant amount of human history.  However it has millions of years of geologic history.  There is at least one place to hike down to the canyon floor.  The hike is only a mile long, and drops 1800 feet.  Going down reportedly is hard, but it is not the problem.

The canyon has been carved over millions of years, at the rate of about an inch every century.  Before being controlled by dams, the spring runoff was significant and could push large boulders along.  This run off, over time has shaped the narrow canyon.  The narrowest point at the base is but 40 feet, “The Narrows.”  The Gunnison accounts for the depth, while the lack of side streams account for the narrowness of the canyon.  The narrowness is also the result of the steep grade of the river.  It descends 2100 feet over the course of the canyon, forty-three feet per mile. 

The black rocks of the canyon are basement rocks (meaning very old), estimated to be 1/7 billion years old.  Normally old rocks are beneath the surface.  Fault line action forced the layers of gneiss and schist to the surface.  They are interlaced with granite-like rock, pegmatite, which makes the lines on the rock.  Painted Wall is the highest cliff in all of Colorado, and would dwarf the Empire State Building.