The Montana river once listed by Guinness as the world’s shortest river was the Roe River.
The Roe runs from Giant Springs to the Missouri River near Great Falls, Montana. Its longest constant channel is about 201 feet, or 61 meters, making it an unusually short named river. The waterway gained national attention through a campaign begun by fifth-grade students at Lincoln Elementary School in Great Falls during the 1980s.
The students first helped secure official recognition of the name “Roe River” and then submitted the claim to Guinness. In 1989, Guinness recognized the Roe as the world’s shortest river, replacing Oregon’s D River. The title was disputed because measurements change with tides, channels and definitions of where a river begins and ends.
Guinness eventually stopped maintaining a shortest-river category in 2006, so the record is no longer an active official Guinness title. That history explains why the wording “once listed” is important. The D River remains a famous rival claimant, but it is in Oregon, not Montana.