Mississippi and Missouri Rivers

Draining two-thirds of the continental United States, the system of the Mississippi (3,782 kilometers) and Missouri Rivers (3,967 kilometers) is the longest waterway in the world. It is also among the most transfigured by human engineering.

Centuries before the arrival of European settlers, these rivers formed the basis of a vast trade network that supported some of the most technologically advanced civilizations in North America. French colonists exploited and modified this network in organizing an extensive trade in fur during the eighteenth century. Following the transfer of political authority to the United States in 1803, the Lewis and Clark expedition the next year, and the advent of steam power in the 1810s, river traffic increased considerably.

The Missouri became the great highway to the West, charting a path of European settlement and Native American subjugation. A flourishing trade in lead, flour, and lumber spurred the growth of towns up and down the Mississippi, most of which were located on high bluffs that offered protection from rising waters. Colorfully portrayed by writers such as Mark Twain and artists such as Karl Bodmer, these rivers became central to the popular imagery and mythology of the nineteenth- century West.

The environmental impact of steamboat traffic, the expansion of commercial agriculture, and urbanization presented western settlers with a host of new problems. The felling of forests to fire steamboat boilers destabilized riverbanks and contributed to unpredictable channel migration. Runoff from plowed fields added considerably to the sediment load in the rivers and facilitated the formation of dangerous sandbars. Floods became more menacing, as well as towns spread onto low-lying land. Meanwhile, direct discharges of industrial and domestic waste damaged the health of downstream users.

It was not until the twentieth century that these problems were attacked systematically. Floods on the Mississippi in 1927 and the Missouri in the 1940s provided the political impetus for federal involvement in river management. Under the principles of multipleuse planning that had been established during the Progressive Era, river channels were straightened and deepened, levees were raised, and water was impounded in reservoirs for irrigation and the generation of electricity.

These large-scale modifications brought economic benefits but imposed heavy environmental and social costs. Fish, wildlife, and human habitats were destroyed; Native American tribes along the Missouri River lost thousands of acres of land to dam and reservoir construction. Embankments and walls squeezed higher volumes of water through narrower channels and increased the risk of inundation for downstream communities that were unable to procure federal flood protection funds.

In the wake of the post-World War II environmental movement, there have been attempts to restore the rivers to their natural condition, including several wetland preservation projects and a plan to reintroduce seasonal fluctuations in flow to the Missouri River. Stricter pollution regulations have resulted in cleaner effluents from industries and cities, although pesticide and herbicide runoff from farms continues to raise health concerns.

Indian-European Trade on the Missouri. In the 1700’s when the trade and travel records were written, the Missouri River was a main artery of European-Indian trade. Commercial companies centered in St. Louis maintained regular contact with trade centers up the river, and in the 1800’s steamboats plied their way upstream with goods and guns to exchange for furs.

Trade centers for exchange were an ancient tradition of American Indian life, and now they eagerly made their way to the trade centers of the European where new goods and materials could be gotten. But the price was dear. For besides the new goods, there came new and fatal diseases—measles, smallpox, cholera, and a variety of fevers—wiping out hundreds and even thousands of people at one blow. Whole tribes that had lived in the region for hundreds of years were wiped out or left in such a fragmentary condition that they joined with other tribes and lost the knowledge of their past identity.

The Pawnees who lived outside the mainstream of commercial traffic were less affected than the others by this holocaust. They lived along the outlying tributaries of the Missouri—the Loup, the Platte, and the Republican—that flow eastward across the present State of Nebraska and join the Missouri at their eastern ends.