The Rock River is a tributary

Tributary

A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...

 of the Big Sioux River

Big Sioux River

The Big Sioux River is a tributary of the Missouri River, long, in eastern South Dakota and northwestern Iowa in the United States. The United States Board on Geographic Names settled on "Big Sioux River" as the stream's name in 1961....

, about 144 miles (231.7 km) long, in southwestern Minnesota

Minnesota

Minnesota is a U.S. state located in the Midwestern United States. The twelfth largest state of the U.S., it is the twenty-first most populous, with 5.3 million residents. Minnesota was carved out of the eastern half of the Minnesota Territory and admitted to the Union as the thirty-second state...

 and northwestern Iowa

Iowa

Iowa is a state located in the Midwestern United States, an area often referred to as the "American Heartland". It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of the French colony of New...

 in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. Via the Big Sioux and Missouri

Missouri River

The Missouri River flows through the central United States, and is a tributary of the Mississippi River. It is the longest river in North America and drains the third largest area, though only the thirteenth largest by discharge. The Missouri's watershed encompasses most of the American Great...

 rivers, it is part of the watershed

Drainage basin

A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

 of the Mississippi River

Mississippi River

The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

.

Course

The Rock River starts in Pipestone County, Minnesota

Pipestone County, Minnesota

As of the census of 2000, there were 9,895 people, 4,069 households, and 2,726 families residing in the county. The population density was 21 people per square mile . There were 4,434 housing units at an average density of 10 per square mile...

, approximately 13 miles (20.9 km) northeast of the town of Pipestone

Pipestone, Minnesota

As of the census of 2000, there were 4,280 people, 1,900 households, and 1,138 families residing in the city. The population density was 1,090.8 people per square mile . There were 2,097 housing units at an average density of 534.4 per square mile...

, and flows initially southwardly through Rock County, Minnesota

Rock County, Minnesota

As of the census of 2000, there were 9,721 people, 3,843 households, and 2,705 families residing in the county. The population density was 20 people per square mile . There were 4,137 housing units at an average density of 9 per square mile...

, and Lyon County, Iowa

Lyon County, Iowa

-2010 census:The 2010 census recorded a population of 11,581 in the county, with a population density of . There were 4,848 housing units, of which 4,442 were occupied.-2000 census:...

, where it turns southwestward into Sioux County, Iowa

Sioux County, Iowa

-2010 census:The 2010 census recorded a population of 33,704 in the county, with a population density of . There were 12,279 housing units, of which 11,584 were occupied.-2000 census:...

. It flows into the Big Sioux River in Sioux County, 6 miles (10 km) north of Hawarden

Hawarden, Iowa

Hawarden is a city in Sioux County, Iowa, United States. The population was 2,478 at the 2000 census. It is located on the Big Sioux River.-Geography:Hawarden is located at , along the Big Sioux River....

.

Along its course the Rock River passes the towns of Holland

Holland, Minnesota

Holland is a city along the Rock River in Pipestone County in the U.S. state of Minnesota. The population was 187 at the 2010 census.-Geography:According to the United States Census Bureau, the city has a total area of , all of it land....

, Edgerton

Edgerton, Minnesota

As of the census of 2000, there were 1,033 people, 435 households, and 287 families residing in the city. The population density was 890.2 people per square mile . There were 477 housing units at an average density of 411.1 per square mile . The racial makeup of the city was 98.84% White, 0.29%...

, Luverne

Luverne, Minnesota

As of the census of 2000, there were 4,617 people, 1,968 households, and 1,247 families residing in the city. The population density was 1,356.1 people per square mile . There were 2,161 housing units at an average density of 634.7 per square mile...

 and Ash Creek

Ash Creek, Minnesota

Ash Creek was the name of a community in Clinton Township in Rock County, Minnesota, United States.-Geography:Ash Creek is located one mile east of U.S. Route 75, 6 miles south of Interstate 90 and 3 miles north of the Iowa stateline.-History:...

 in Minnesota; and the towns of Rock Rapids

Rock Rapids, Iowa

Rock Rapids is a city in Lyon County in the northwestern part of the U.S. state of Iowa, an area known for its strong Dutch heritage and conservative politics. It is the county seat of Lyon County and home to Central Lyon Schools. The population was 2,549 in the 2010 census, a decline from 2,573...

, Doon

Doon, Iowa

Doon is a city in Lyon County, Iowa, United States, along the Rock River. The population was 533 at the 2000 census. The BNSF, or Burlington, Northern & Santa Fe Railway, passes through Doon.-History:...

 and Rock Valley

Rock Valley, Iowa

Rock Valley is a city in Sioux County, Iowa, United States, along the Rock River. The population was 2,702 at the 2000 census.-Geography:Rock Valley is located at ....

 in Iowa.

Tributaries

In its upper course in Minnesota, the river collects the East Branch Rock River, about 15 miles (24.1 km) long, which flows for its entire length in Pipestone County. In Iowa, it collects the Little Rock River

Little Rock River

The Little Rock River is a tributary of the Rock River, long, in southwestern Minnesota and northwestern Iowa in the United States. Via the Rock, Big Sioux and Missouri rivers, it is part of the watershed of the Mississippi River....

 just south of Doon.

See also

• List of Iowa rivers
• List of Minnesota rivers
• Rock River
  Rock River
  Rock River may refer to:Streams:* Rock River , a tributary of the Mississippi River in Wisconsin and Illinois in the USA* Rock River , a tributary of the Big Sioux River in Minnesota and Iowa in the USA...
  
  (for other Rock Rivers)