I flew in a Piper Cub Plane over Ted Turners Ranch and Chased His Bison...I have Picniced where the Madison and Jefferson Rivers come together to form the Headwaters of the Missouri River, just outside Three Forks Montana...Beautiful...and cold...I have traveled the Missouri River from it's Beginning to it's End twice...Following the Louis and Clark Trails...Some Facts about the Mighty Mo...
Missouri River Facts
How did the Missouri River come to be?
The present course of the Missouri was formed about 115,000 years ago when streams flowing eastward from the Rocky Mountains encountered the western edge of the Illinoisan ice sheet. These streams were diverted southward until the southern edge of the glacier was reached near present day Kansas City. From there, the river flowed east along the southern border of the glacier, through what is now central Missouri.
How long is the Missouri River?
From Three Forks, Montana, to St. Louis, the river is 2,300 miles long.
What was the historical river basin like?
Eighty-seven percent of the basin’s 338.5 million acres was originally prairie. The floodplain of the Missouri and its tributaries were a mixture of grasslands, forests and wetlands.
What did the original river look like?
The river was filled with islands, side channels flowing around islands, quiet backwaters and marshes as well as the main channel of the river. Today’s river has a nine-foot navigation channel and, at 1,000 feet wide, is roughly half the width it used to be before it was channelized.
What were the March and June rises?
Prior to upstream reservoir construction, the Missouri River experienced two general periods of high water. The first, often referred to as the March rise, was caused by snow melt on the plains and the breakup of ice in the main channel and tributaries. The second, called the June rise, resulted from run-off of melting mountain snow and rainfall throughout the basin. The reservoirs were constructed to help minimize the frequent downstream flooding from these rises.
Were there any benefits to the rises?
The natural spring rises in river flow often flooded nearby land. The flood waters deposited sediments rich in organic matter. This increased productive plant communities along the river, particularly marshes that produced huge quantities of insects and other small invertebrate animals that served as important food supplies for fish and waterfowl, including ducks and geese.
Changing the River – A time line of the historical Missouri
1804–1806 — The first formal exploration of the Missouri River by Lewis and Clark. They saw the value of the river as a convenient avenue of travel into the Great Plains and Rocky Mountains that would help increase fur trading with the American Indians. 1838 — Removal of snags to promote steamboat traffic.
1867 — The first government survey of the Missouri River was made by Charles Howell.
1862–1902 — Congress appropriated $8 million for channel improvements. This resulted in the construction of a 5.5 foot-deep navigation channel for the first 44 miles of the river upstream from the mouth to Augusta in St. Charles County.
1933 — Construction of the first major dam, Fort Peck, on the Missouri River’s main stem begins in Montana.
1944 — The Flood Control Act required a basinwide plan, known as the Pick-Sloan Plan. The plan recognized the need to provide for multiple uses, such as irrigation, navigation, hydropower, flood control, water quality, water supply, fish and wildlife and recreation. The major result of this plan was the construction of an additional six dams on the main stem Missouri to join the Fort Peck Dam.
1945 — The Rivers and Harbors Act established the dimensions of the present navigation channel which is 9 feet deep and 300 feet wide. The Rivers and Harbors Act also required the navigation channel to be extended to Sioux City, Iowa.
What about the fish?
Together with the removal of snags, the loss of good habitat has caused an estimated loss of more than 80 percent of the fish in the river. Changes in habitat and increased water clarity due to the trapping of sediments in the main stem reservoirs has caused an increase in the numbers of species such as skipjack herring, gizzard shad, white bass, bluegill, white crappie, and the emerald, river and red shiners. In Missouri, two large river species, the pallid sturgeon and the flathead chub, are in serious decline. In Nebraska, serious declines in seven species of minnow, burbot and sauger have occurred. If trends continue, some of these species may become lost from the Missouri River system. The loss of fish species signifies damage to the river’s ecosystem.
Have land-use changes affected the Missouri river?
Changes in the river have been accompanied by land use changes as well, particularly on the channelized lower river. Between 1892 and 1982 on floodplain land between Sioux City, Iowa, and St. Louis, cultivated land increased 4300 percent, while tree cover declined 41 percent, wetlands declined 40 percent, sandbars declined 97 percent, and grasslands declined 12 percent.
What’s the Missouri River like today?
Channelization and dam building have greatly changed the Missouri River. Today, 67 percent of the Missouri is either channelized for navigation (650) miles or impounded by dams (903 miles). Most of the remaining free-flowing portions of the river are near the headwaters in Montana. Channelization has resulted in the lower river being about 50 percent narrower. Most of the loss in width has been in the more biologically productive off-channel back waters and marshes.
