What is the longest river in the U.S.?

The Missouri River is recognized as the longest river in the United States. Stretching approximately 2,341 miles, it flows from the Rocky Mountains in Montana through several states, including North Dakota, South Dakota, Nebraska, Iowa, Kansas, and Missouri, before it joins the Mississippi River.

This distinction is significant in understanding U.S. geography and hydrology. The Missouri River holds importance historically and economically, serving as a vital transportation route, a source of water for agriculture, and a habitat for wildlife. Its length surpasses that of the Mississippi River, which is often mistaken for being the longest due to its prominence in cultural and historical contexts.

The Colorado River and Ohio River, while important watercourses, do not approach the length of the Missouri River. Thus, knowing that the Missouri River is the longest helps to clarify the river systems in the United States.