Rock River (Iowa)
|Districts||Sioux County, Iowa, Lyon County, Iowa, Rock County, Minnesota, Pipestone County, Minnesota|
|Mouth||Big Sioux River|
|- elevation||1,171 ft (357 m)|
|U.S. Geological Survey Geographic Names Information System: Rock River (Iowa)|
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 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. National Hydrography Dataset high-resolution flowline data. The National Map, accessed March 30, 2011
- 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.