Cottonwood River

About

Cottonwood River, Minnesota — 1854 German Colonization, 1840s-1880s Logging, 1990s-2010s Cottonwood Trail 100-mi New Ulm. Long before the plow, the Cottonwood River valley was ancestral homeland of the Dakota — the Mdewakanton and Wahpekute — and the Ojibwe. The river took its name from the cottonwood (Populus deltoides) trees that grew along its banks, groves dense enough that the Dakota called the whole waterway Wáǧa Ožú Wakpá. That world was reshaped in a compressed span: the 1851 Treaty of Traverse des Sioux, the U.S.-Dakota War of 1862-1863, and the Dakota forced exile that followed. The 1862-1863 conflict ended Dakota presence in the Cottonwood River valley by 1863.

The river's pivotal European chapter came in 1854, when a German colonization association from Chicago selected a spot on the south bank of the Minnesota River near the mouth of the Cottonwood to found the settlement that became New Ulm. Settlement brought industry. From the 1850s through the 1910s, the watershed was logged to feed the Cottonwood County sawmill era of 1860-1890, the St. Paul, Minneapolis & Manitoba Railway's expansion beginning in the 1870s, and Minnesota's flour milling industry of the 1880s onward. The Windom and Mountain Lake sawmills, a Cottonwood County furniture industry running from 1870 to 1895, and the Cottonwood Brick & Tile Company were the major operators. The exhaustion of the bur-oak and basswood stands around 1895, the start of forestry conservation in 1910, and the Cottonwood Project construction of 1935-1940 together ended large-scale logging.

The river's hydrology was first studied in earnest in 1869, when the Cottonwood River Survey — led by Minnesota State Engineer W.R. Marshall — produced the first comprehensive hydrological study of the watershed, documenting streamflow records from 1855-1868 and the land survey of 1868-1869. That survey became the basis for the 1935-1940 Cottonwood Project, a flood-control effort that transformed the 175,000-acre watershed. Cottonwood Lake, completed in 1940, stands as the third-largest Army Corps of Engineers lake in Minnesota, with 1,250 acres of water surface and 32 miles of shoreline.

The modern story is one of both use and repair. In 2024 the Cottonwood Restoration Program — a joint Army Corps of Engineers St. Paul District and Minnesota DNR effort — removed seven fish-passage barriers and restored 22 miles of riparian buffer. That same year Cottonwood Lake drew 184,000 visitors, a 15 percent increase over 2018, and it supports one of the densest populations of walleye and northern pike in its basin. The 1990-2000 Minnesota DNR Cottonwood River Basin Study had already identified the watershed's major water-quality challenges, the direct legacy of an agricultural landscape where nearly nine acres in ten are cultivated.

For paddlers, the Cottonwood runs best at 225 to 650 CFS on gauge 05317000, comfortably around its 440 CFS average. As the Cottonwood River State Water Trail, it offers a working-prairie float with deep roots — a Dakota name, a German colonial founding, a logging boom, and a New Deal-era flood project all layered into 67 miles of southwestern Minnesota river.