Missouri River of Hope and Change Earthcache EarthCache

Geology:
The Missouri River is the longest river in the United States. It stretches 2,341 miles from its headwaters at Three Forks, Montana to where it meets the Mississippi River at St. Louis Missouri. Its watershed covers 1/6th of the United States, encompassing 530,000 square miles of land.

At the end of the Ice Ages, the Missouri River was diverted to (or formed at) its current location as a place where the melting (and thus retreating) glaciers dumped their water. The result was a fast and yet shallow river bed that cut across the plains to the south and west of the terminal moraines. These terminal moraines marked the furthest southerly extent of the the glaciers. Because the melt water was coming off the glacier in so many places, it joined the Missouri River over a wide surface area, creating and eroding the mounded tills (we call them hills now) the now exist just east of this river valley in western Iowa. Because of the glaciated landscape that preceded this river, the "bedrock" is relatively resistant to weathering and thus the valley that is cut by the river has not left a deep channel but rather a shallow river, "The Big Muddy" that has for centuries carried the sediment of the upper portions of the geologic column downriver to the Mississippi.

Known as the Big Muddy, the Missouri River is no longer the mighty force it once was. Each spring when snow melted and rain fell on the Great Plains, the river would rise and carve a new course in the valley, devouring farmlands, forests, railroads, towns, and even state lines in the process. The scene would repeat itself in early summer when snowmelt from the Rocky Mountains flowed downstream and caused the river to rise even more.

In late summer, flows would subside and the river would settle into the new bed it had made. The rivers main channel, which spanned a mile or more in some areas, was dotted with islands and laced with sandbars stripped of vegetation by the high flows of the river.

Flanked by slow-moving side channels, chutes, and backwaters, the river's course was ever changing, and left behind a trail of oxbow lakes, wetlands, and forests of cottonwoods and willows.

The need for safe and dependable river transportation and the protection of bottom-land farms and towns moved people to tame the river. Work began to remove the snags, which had a habit of sinking steamboats. Six huge dams were built on the river in Montana, North and South Dakota, and Nebraska to hold back spring flows that could be released later for navigation, irrigation, and power generation. In the process, one-third of the river's length was turned into Reservoirs. The lower third of the river from Sioux Falls, Iowa to St. Louis Missouri was forced into the 600-foot wide self-scouring channel you see here. In all but the wettest years, levees keep the waters from spilling out too far into the valley. Finally, the river's course was straightened, shaving 205 miles from its length and creating lakes such as the Desoto Bend and Carter Lake in the process.

Efforts did not entirely tame the river but they did leash it and now, only a third of the river, including two sections along Nebraska's northern border, remains in a natural or semi-natural state. While the changes benefited society, they did so at the expense of the environment. Change is coming once again, this time with the hope of restoring the ecosystem of the river.

Logging Requirements:
Send the answers to #1-#4 to me through my geocaching profile (Since the advent of the "new" Message the Owner feature, I prefer messages through that venue). .

1. List the name "GC1XHG1 Missouri River of Hope and Change Earthcache" in the first line of your email. Also, list the number of people in your group.
2. From anywhere on the bridge, attempt to discover evidences of man's efforts to tame the river, listing at least TWO that you can see from the bridge
3. Based on the information above, what do you believe to be the biggest loss to the area because of the taming of the Missouri River?
4. Based on your reading of the above, what has been the geological role of the Missouri River historically? What role do you imagine it playing geologically in the future?
5. (Per current gc.com guidelines, photos are no longer allowed to be required. HOWEVER they are encouraged, since they can help clarify that you have visited the location if your other logging requirement answers are vague). Take a picture of yourself and your GPS from ON the bridge, with bridge / river visible behind you. Post this picture in your profile.

Ecology/History:
For more than a century, man has worked to tame the natural cycles of the Missouri River and exploit its power. There are benefits. Dams hold back floodwaters that once threatened bottom-land farmers and residents of Omaha, Council Bluffs, and other towns along its banks. A narrow and deep navigation channel was created to make barge shipping more efficient. Stable water levels have assured these communities along the river a constant, reliable water supply. And water, released from the dams generates hydroelectric power.

But there are also costs. Lost in these transformations were 154,000 acres of aquatic habitat 354,000 acres of river-dependent habitat. Islands and sandbars are mostly gone as are the side channels, chutes, backwaters, and half of the river's surface area. Most of the sediment that once coursed the river and is critical to river function is now trapped in upstream reservoirs.

By 2008, of the 67 species native to the Missouri River, 51 are now rare ore reduced in number, or in the case of the pallid sturgeon, endangered. Birds and mammals also suffer, including the threatened piping plover and endangered interior least stern, both of which require sandbars for nesting habitat. This channelized version of the river also limits opportunities for hunters, anglers, and wildlife watchers and other outdoor enthusiasts to experience the natural diversity that an unbridaled river provides.

The U.S. Army Corps of Engineers, which manages the river has been working to regain the lost habitat by reopening chutes and backwaters and modifying or adding structures in the main channel to create sandbars and other shallow water habitat. Efforts will also be made to mimic the natural cycles of the spring rise to ensure the continued existence of declining native species.

Resources:
Signage on the bridge
Trimble, Donald. The Geologic Story of the Great Plains. Reprint with minor revisions of Geological Survey Bulletin 1493. 1990. ISBN: 0-9601652-8-2.