The commonest appellation was Green, supposed to have been derived from a trapper of that name.

Just when the term "Colorado" was first applied to the lower river is not now known.

It bore several names, but finally Colorado took first place because of its appropriateness.

Both the walls and the water are usually red, though the name is undoubtedly derived from the colour of the water.

Green River is frequently as red as any river could be.