Adsactly Education: Missouri River

The Missouri River is the longest in North America running 2,341 miles (3,767 km) from it’s headwaters in Yellowstone park to it’s confluence with the Mississippi. The drainage basin for the Missouri is a significant fraction of the center of the US and Canada.

The Missouri is known as ‘the Big Muddy’ and it’s very character carries risks of catastrophic flooding and a lack of flow depending on he season. Of all the great rivers of the west it is probably most at peril due to global warming.

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The River and It’s Course

Due to the way the Missouri was originally mapped, there is no definite headwaters. It officially begins at the confluence of three rivers, the Jefferson, the Gallitin and the Madison. The Madison begins just a few miles from the headwaters of the Snake in Madison Lake in Yellowstone National Park as the Firehole which flows east to the confluence.

The Gallatin runs out of Gallatin Lake in Yellowstone while the Jefferson rises up in the Rocky Mountains of Montana and joins the Beavrhead before the confluence of the three. By the time it is actually called the Missouri (at Missouri Headwaters State Park in Montana) it is already a pretty good sized river.

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From the confluence the river flows northeast to Great Falls, Montana. It then flows generally east across the plains of Montana to North Dakota where the Yellowstone joins it from the southwest. The Missouri flows generally east through much of North Dakota before it turns southeast to run through South Dakota and into Nebraska. It forms the boundary between Nebraska and Iowa then between Kansas and Missouri. The river then flows east through Kansas City and on to St. Louis where it joins the Mississippi at the Missouri and Illinois border.

The Missouri drains an enormous watershed that totals over 500,000 sq. miles (1,300,000 sq. km) which is over five percent of the continent of North America. Though the population of the drainage area is only about 12,000,000 it provides a significant fraction of the grain, meat and fowl that feeds North America.

The flow rate for the Missouri is prodigious with an average of 87,500 Cubic Feet Per Second that can swell to 750,000 CFS during flooding. At it’s confluence with the Mississippi the Missouri provides roughly 45% of the flow to the combined rivers.

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Geology

Around 50 million years ago the Rocky Mountains rose to form the western edge of a vast sea that covered the entire area between the Arctic Ocean and the Gulf of Mexico. The sediment from that sea forms much of the basis for the land that the Missouri drains. An uplift caused the sea to retreat and the area between the Rocky Mountains and the Appalachian Mountains became the home to many rivers and watercourses.

As the Rocky Mountains wore down a gentle tilt from west to east cast the character of the Great Plains. The Missouri drainage was probably split into three segments. The northern drained into Hudson’s Bay, the center and southern flowed toward what is now the Mississippi.

The ice ages changed the character of the river and the basin that we see today. As the ice ground down from the north the area was filled with huge inland lakes which spilled over making many of the dry watercourses that we see today. The end of the last ice age (roughly 15,000 years ago) marked the course of the current rivers.

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As the river and it’s tributaries flowed through the sediment that created the surface of the Great Plains it carried vast amounts of silt as it cut new channels through the plains and eventually carried all the way to the Gulf of Mexico and the Delta of the Mississippi.

History

Almost as soon as the ice left (15,000 years ago) the people appeared. The silt that was carried downstream made huge flats of very rich soil that included a wide diversity of (edible) plants and American Bison by the millions. It is here, in the drainage of the Missouri and the Mississippi that North American agriculture began. Indigenous people soon learned to cultivate squash and corn and communities arose on a scale unseen in the rest of North America. A vast growing and trading network existed on the banks of the rivers.

Buffalo were numerous and provided the natives not only food but the hides provided clothing and even temporary shelter. Prior to the introduction of the horse, Buffalo hunting was a very cooperative process which generally involved herding a group of the foul tempered beasts into an enclosure or off a cliff. It was hard and dangerous but the rewards were mountains of good meat and leather. It required the work of many to get and store this resource which gave rise to the system of families, clans and tribes. Working together allowed all to eat and prosper.

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Herbs and vegetables were numerous in the area so the diet was varied and rich. A rich diet and cooperative living led to a large population rise. More people and more time that was not needed just to be able to eat led to advanced tool making and art both practical and esthetic. Items of beauty were highly regarded and heavily traded. Tools and implements were prized possessions and the techniques for making them spread rapidly.

The natives had little written record so most of the information that we have today is from archeological findings and the records of the earliest European contacts. In the second part of this project we will explore the European expansion through the drainage of the Missouri River as well as the shape and form of the river today and how it got that way.

While the words and ideas in this post are strictly those of the author this source was referred to by me to insure numerical and historical accuracy.
Wikipedia: Missouri River

Unsourced Photos are used courtesy of the author.