The longest river in the United States is the Missouri River.
Geography

The longest river in the United States is the Missouri River.

At around 2,340 miles in length, it is slightly longer than the Mississippi River, which is about 2,320 miles long.

The longest river in the United States is the Missouri River.

At around 2,340 miles in length, it is slightly longer than the Mississippi River, which is about 2,320 miles long.