Lieutenant Wheeler several times claims the honour of naming it (1868-71), but the name occurs on Lieutenant Ives's map of 1858.

This plateau breaks sharply along its south-west line to the lowland district, and on its north-westerly edge slopes to the Little Colorado.

It bears a noble pine forest, and from its summit rise to over 12,000 feet the volcanic peaks of the San Francisco Mountains.

Its northern edge is the Grand Canyon, which separates it from its kindred on the other side.

These and the Colorado Plateau rise to from 6000 to 8000 feet above sea-level, and it is through this huge mass that the river has ground out the Grand Canyon, by corrading its bed down tremendously, the bottom at the end being only 840 feet above the sea, whereas the start at the mouth of the Little Colorado is 2690.