Sunrise on the Missouri River
The Missouri River is a tributary of the Mississippi River that is born at the confluence of the Madison, Jefferson, and Gallatin rivers in Montana, and flows into the Mississippi River north of St. Louis, Missouri. At over 2,300 miles in length, it drains approximately 1/6th of the North American continent. Depending on the point from which it is measured (long story) it is either considered the longest or 2nd-longest river in the United States. In any case, the combined Missouri-Mississippi river system is the 4th-longest river in the world.

The Missouri River is called "Big Muddy" due to the high silt content in its flow. This feature that is highly visible at its confluence with the Mississippi.

The Missouri River is a source of outdoor recreation and adventure in the state of Missouri. Visitors will find plenty to do on the Missouri river, from Missouri rafting to Missouri fishing.