Colorado River

one of the great streams of North America. It is formed by the junction of the Green, whose head waters rise in Wyoming, and the Grand, whose head waters rise in Colorado. It flows southwesterly through Utah, Arizona, Nevada and Mexico, receives the Gila, and empties into the Gulf of California. The Green emerges from a series of canons, 1,500 feet deep. The main Colorado passes through four canons, the Marble Canon, 60 miles in length and 3,600 feet deep; the Grand Canon, 200 miles long and from 4,000 to 7,000 feet deep--the greatest canon in the world ; the Callville Canon, 7,000 feet deep, with terraced cliffs piled with the ruins of cities; and, lastly, the Black Canon, 25 miles long and 1,000 to 1,500 feet deep. The lower 612 miles of the river, including the Black Canon, are navigable for steamers as far as Callville, Nevada.

These great canons have been cut by the current. Particles of sand in the swiftly running water have chipped off the sandstone like chisels, and worn channels, in places a mile and a half deep. Clear water free from grit has little erosive or scouring power. Many other rivers in the world have worn still deeper channels; but their cliffs have been worn down by rain, so that, instead of a narrow gorge, a wide valley has been formed. The wonderful canons of the Colorado are in a well nigh rainless region. The cliffs stand much as when left by the current of the river. To those fond of statistics, it may be said that 750,000,000,000,000 cubic feet of rock have been chiseled out and carried away by the Colorado River. At the rate at which sediment is now carried by the current, 10,000,000 years would be required to do the work.

Of late the Lower Colorado has given the Southern Pacific Railway trouble by leaving its banks and flooding a large, low area, known as Salton Desert. The mouth of the river is a vast mud delta in which the Indian sows his September seed.

See Grand Canyon; Salton Sea; Irrigation