Cottonwood River

The Cottonwood River is a tributary of the Minnesota River in southwestern Minnesota. It is about 152 miles long and drains 1,313 square miles, most of it farmland. The river rises southwest of Balaton in Rock Lake Township, Lyon County, on the Coteau des Prairies. From there it flows east through southern Redwood County, the northeastern corner of Cottonwood County and northern Brown County, passing Sanborn and Springfield. Near its mouth it runs through a wooded valley in Flandrau State Park and joins the Minnesota River just southeast of New Ulm. The name translates the Dakota name Wáǧa Ožú Wakpá, and the river was also known historically as the Big Cottonwood River. A dam once formed a lake in the state park. Floods in 1965 and 1969 washed it out, and it was not rebuilt.

The Minnesota DNR made the river a state water trail in 1996. The canoeable portion runs 58 river miles from Springfield to the Minnesota River near New Ulm and has no major rapids. The DNR names the Highway 4 access south of Sleepy Eye and the County Road 11 access as the best places to start a trip. For the take-out it suggests the Cottonwood Street Bridge near Highway 15, or continuing to the Courtland access on the Minnesota River. The DNR focuses snag removal and maintenance between river mile 31.4 and the confluence. Flandrau State Park sits at river mile 6. The Redwood-Cottonwood Rivers Control Area rents canoes and kayaks and holds an annual canoe trip that starts at Iberia Landing on County Road 4.

The USGS gauge near New Ulm recorded a mean flow of 381 cubic feet per second from 1909 to 2005. The highest flow on record was 28,700 cubic feet per second, on April 10, 1969.