Cadillac Desert: The American West and Its Disappearing Water

by Marc Reisner

The Missouri River is, after the Columbia, the biggest river in the American West, though it takes it a long time to grow to size. The Columbia, rising prodigiously out of the rain forests of the Purcell Mountains in Canada, is like a Clydesdale horse, big and powerful at birth. The Missouri, still small after going a distance in which the Columbia becomes huge, is a scavenger of a river, struggling to attain size. It isn’t until the North Dakota border, nearly a thousand miles from its source, where the Yellowstone River adds a surge out of the Absaroka and Big Horn Mountains, that the Missouri begins to look impressive. The river turns south, capturing the Platte and the Niobrara and the Kansas and the James, and then east again. By the time it has gone two and a half thousand miles and joined the Mississippi, it is the twelfth-longest river in the world; however, because of the aridity of the basin it drains, the Missouri is only the seventh-ranking river in the country in terms of annual flow. Meager for its huge watershed and length, the virgin Missouri also flowed erratic in the extreme. At Hermann, Missouri, the discharge to the Mississippi has been measured as low as forty-two hundred cubic feet per second and, in June of 1944, as high as 892,000 cubic feet per second, enough water in a day to satisfy New York City for a year. Its course was as unpredictable as its volume. Flowing across the glacial outwash of the plains, the Missouri is unconfined by a true canyon...