Roe River is the smallest river on Earth. It is located in Great Falls, Montana with a length of more or less than 200 feet between these two areas: the Giant Springs, a large spring found near Great Falls and the Missouri River which is the longest river in North America. As a matter of fact, the Guinness Book of World Records, after a successful campaign of school children, recognized the Roe River in 1989 as the smallest and shortest river in the world.
However, please note that before 1989, Oregon’s D River located in Lincoln City, Oregon was recognized by Guinness Book of World Records as the world’s shortest and smallest river with a length of more or less than 440 feet.