Rock River (Big Sioux River)
The Rock River is a tributary of the Big Sioux River, about 144 miles (232 km) long, in southwestern Minnesota and northwestern Iowa in the United States. Via the Big Sioux and Missouri rivers, it is part of the watershed of the Mississippi River. The river's name comes from a prominent rocky outcrop about 175 feet high (designated "The Rock" on Joseph Nicollet's 1843 map of the area) of reddish-gray Sioux Quartzite, about 3 miles (5 km) north of Luverne The outcrop of quartzite is contained in Minnesota's Blue Mounds State Park.
|District||Sioux County, Iowa, Lyon County, Iowa, Rock County, Minnesota, Pipestone County, Minnesota|
|Mouth||Big Sioux River|
|1,168 ft (356 m)|
The Rock River starts in Pipestone County, Minnesota, approximately 13 miles (21 km) northeast of the town of Pipestone, and flows initially southwardly through Rock County, Minnesota, and Lyon County, Iowa, where it turns southwestward into Sioux County, Iowa. It flows into the Big Sioux River in Sioux County, 6 miles (10 km) north of Hawarden.
In its upper course in Minnesota, the river collects the East Branch Rock River, about 15 miles (24 km) long, which flows for its entire length in Pipestone County. In Iowa, it collects the Little Rock River just south of Doon.
- U.S. Geological Survey Geographic Names Information System: Rock River (Big Sioux River)
- U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data. The National Map, accessed March 30, 2011
- Upham, Warren (1920). Minnesota Geographic Names. Minnesota Historical Society. p. 466. Retrieved 30 November 2019.
- Columbia Gazetteer of North America entry
- DeLorme (1998). Iowa Atlas & Gazetteer. Yarmouth, Maine: DeLorme. ISBN 0-89933-214-5.
- DeLorme (1994). Minnesota Atlas & Gazetteer. Yarmouth, Maine: DeLorme. ISBN 0-89933-222-6.
- U.S. Geological Survey Geographic Names Information System: Rock River
- U.S. Geological Survey Geographic Names Information System: East Branch Rock River
- Waters, Thomas F. (1977). The Streams and Rivers of Minnesota. Minneapolis: University of Minnesota Press. ISBN 0-8166-0960-8.