The Little Sioux is a river in the United States. It rises in southwest Minnesota near the Iowa border, and continues to flow southwest for 221 miles across northwest Iowa into the Missouri River at Little Sioux. Its tributaries include the Ocheyedan River, Maple River and the West Fork of the Little Sioux River. The Little Sioux River is integral to the Nepper Watershed Project, a major Iowa flood control and soil conservation program that was introduced in 1947.

The Little Sioux Valley figures prominently in folklore about the nineteenth century outlaw, Jesse James, who reportedly used the secluded valley, with its wooded ravines, as a hideout and a route north to Minnesota.

Geologically, the Little Sioux rises in a region of glacial potholes near the "Iowa Great Lakes" (Spirit Lake, and East and West Okoboji). It then traverses a rich agricultural region on its way to the Loess Hills, from which it then flows out onto the floodplain of the Missouri River. Through much of its middle course, the Little Sioux is a relatively wild meandered stream, with excellent canoeing, camping, and fishing opportunities. However, from downstream of Smithland, Iowa, the river has been channelized and environmentally degraded.

See also

• List of Iowa rivers

Rivers of Iowa | Rivers of Minnesota | Tributaries of the Missouri River

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