The North 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 Des Moines River

Des Moines River

The Des Moines River is a tributary river of the Mississippi River, approximately long to its farther headwaters, in the upper Midwestern United States...

 in south-central 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...

. It is 103 miles (165.8 km) long and drains an area of 349.2 square miles (904.4 km²). Via the Des Moines River, 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...

.

The North River rises northeast of Casey

Casey, Iowa

Casey is a city in Adair and Guthrie Counties in the U.S. state of Iowa. The population was 478 at the 2000 census.The Guthrie County portion of Casey is part of the Des Moines–West Des Moines Metropolitan Statistical Area...

 in southern Guthrie County

Guthrie County, Iowa

-2010 census:The 2010 census recorded a population of 10,954 in the county, with a population density of . There were 5,756 housing units, of which 4,544 were occupied.-2000 census:...

 and flows generally eastwardly through Adair, Madison

Madison County, Iowa

-2010 census:The 2010 census recorded a population of 15,679 in the county, with a population density of . There were 6,554 housing units, of which 6,025 were occupied.-2000 census:...

 and Warren counties, past Carlisle

Carlisle, Iowa

Carlisle is a city in Warren and Polk counties in the U.S. state of Iowa. The population was 3,497 at the 2000 census. The city is part of the Des Moines–West Des Moines Metropolitan Statistical Area....

, into southeastern Polk County

Polk County, Iowa

Polk County is a county located in the U.S. state of Iowa. The population was 430,640 in the 2010 census, an increase from 374,601 in the 2000 census. The county seat is Des Moines, which is also the capital city of Iowa...

, where it joins the Des Moines River 10 miles (16.1 km) southeast of Des Moines

Des Moines, Iowa

Des Moines is the capital and the most populous city in the US state of Iowa. It is also the county seat of Polk County. A small portion of the city extends into Warren County. It was incorporated on September 22, 1851, as Fort Des Moines which was shortened to "Des Moines" in 1857...

.

In Madison County, it collects a short tributary known as the North Branch North River.