The Loutre River is a 58.4-mile-long (94.0 km)[1] tributary of the Missouri River in the United States. The Loutre River begins in Audrain County. It flows into the Missouri River from the north in Montgomery County opposite the town of Hermann. Loutre, meaning "otter", was applied to the river by French trappers. At Mineola, the river has a mean annual discharge of 98 cubic feet per second.[2]