Shell River

The Shell River is a 47.8-mile-long (76.9 km) tributary of the Crow Wing River in north-central Minnesota in the United States. Via the Crow Wing River, it is part of the watershed of the Mississippi River, draining a rural region.
The river was named for mussel and clam shells found along the river and along Shell Lake, its origin.

Source: Wikipedia https://en.wikipedia.org/wiki/Shell_River_(Minnesota)