The Missouri River suffers heavily from people trying to control it's path. Almost one third of the entire river has been altered by dams or channels. Many structures have been addded to the banks of the Missouri in order to control it. The river has actually been shortened by 46 miles. As a result of increasing depth, the river that originally had 161 islands in it's flow now has only 18.

   The commercial fishing industry on the Missouri river has been hit by hard times. The annual harvests have been decreased by as much as 80 %. There are 34 species of fish in the river that are now considered rare, threatened or endangered.

   The dams to the north have created erosion problems, and at the request of landowners and farmers, the National Park Service has used concrete on the river banks to stop the natural erosion. This bank stabilization alters the natural current and path of the river, destroys wildlife habitat and increases the likelihood of flooding by destroying wetlands.

   The "Big Muddy", as the Missouri River is nicknamed, has been listed as the second most endangered River, only preceded by the Columbia River in Washington State.