All these canyon names, from Green River Valley to the Grand Wash, were applied by Powell.

Between Labyrinth and the next canyon, Gray, so called from the colour of its walls, 2000 feet high, is Gunnison Valley, where the river may first be easily crossed.

Here the unfortunate Captain Gunnison, in 1853, passed over on his way to his doom, and here, too, the Old Spanish Trail led the traveller in former days toward Los Angeles.

The Denver and Rio Grande Western Railway has taken advantage of the same place to cross.

The 36 miles of Gray are hardly more than a continuation of the Canyon of Desolation's 97 miles.