First Through the Grand Canyon —— Being the Record of the Pioneer Exploration of the Colorado River in 1869-70

-----

ISBN: 9781332012916 出版年：2016 页码：325 John Wesley Powell Forgotten Books

The Colorado River of the West is formed in southeastern Utah by the junction of the Grand and Green rivers. For hundreds of miles it flows through a series of profound chasms, in many places from 4,000 to 6,000 feet deep, and rising nearly vertically for a considerable distance above the water. These canons are from one to fifteen miles wide at the top. The most famous of them is the Marble-Grand canon (really continuous, although it goes under two names, the Marble and the Grand). Through this vast gorge the Colorado drops 2,330 feet in 283 miles, the current sometimes attaining a velocity of twenty-five miles an hour. The river itself varies in width from seventy-five feet to a quarter of a mile. In the narrowest places it has at times a depth of over 100 feet.