It is the largest tributary of the Blue Earth River, draining 31% of its watershed.

[8][9] Its largest tributaries are the Cobb and Maple Rivers, which it collects from the south approximately six and eight miles (10 km/13 km) upstream of its mouth, respectively.

Extensions of the Big Woods, a tract of hardwoods that has since been largely converted to agricultural use, historically followed the river's riparian corridor southward.

According to the Minnesota Pollution Control Agency, approximately 84% of the larger watershed of the Blue Earth River is used for agricultural cultivation, primarily that of corn and soybeans.

[4][10] At the United States Geological Survey's stream gauge near the community of Rapidan, two miles (3 km) upstream from the river's mouth, the annual mean flow of the river between 1940 and 2005 was 549 cubic feet per second (16 m³/s).