World's Shortest River

Updated: February 2, 2026

The Roe River, which flows about 200 feet from Giant Springs to the Missouri River near Great Falls, was once recognized by Guinness World Records as the world's shortest river after a successful campaign by local schoolchildren, but that record category has since been discontinued. The Roe still informally competes with Oregon's D River for the title of shortest river, and both have been measured at different lengths on different occasions. Giant Springs, the source of the Roe River, is one of the largest freshwater springs in the United States.

The longest river associated with Montana is the Missouri River, which is about 2,341 miles long from its headwaters near Three Forks, Montana, to its confluence with the Mississippi River, with a little over 700 of those miles flowing within Montana's borders.

Updated: February 2, 2026