The Cannonball River is a tributary of the Missouri River

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...

, approximately 135 mi (217 km) long, in southwestern North Dakota

North Dakota

North Dakota is a state located in the Midwestern region of the United States of America, along the Canadian border. The state is bordered by Canada to the north, Minnesota to the east, South Dakota to the south and Montana to the west. North Dakota is the 19th-largest state by area in the U.S....

 in the United States

United States

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

.

It rises in the Little Missouri National Grassland

Little Missouri National Grassland

Little Missouri National Grassland is a National Grassland located in western North Dakota, USA. At 1,033,271 acres , it is the largest grassland in the country. Enclaved within its borders is Theodore Roosevelt National Park, which is managed by the National Park Service...

, in the badlands

Badlands

A badlands is a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded by wind and water. It can resemble malpaís, a terrain of volcanic rock. Canyons, ravines, gullies, hoodoos and other such geological forms are common in badlands. They are often...

 north of Amidon

Amidon, North Dakota

As of the census of 2000, there were 26 people, 14 households, and 9 families residing in the city. The population density was 41.2 people per square mile . There were 17 housing units at an average density of 26.9 per square mile...

 in northern Slope County

Slope County, North Dakota

There were 313 households out of which 30.0% had children under the age of 18 living with them, 64.5% were married couples living together, 3.8% had a female householder with no husband present, and 28.8% were non-families. 27.2% of all households were made up of individuals and 10.5% had someone...

. It flows ESE past New England

New England, North Dakota

As of the census of 2000, there were 555 people, 266 households, and 155 families residing in the city. The population density was 1,106.1 people per square mile . There were 320 housing units at an average density of 637.8 per square mile . The racial makeup of the city was 98.20% White, 0.54%...

, Mott

Mott, North Dakota

As of the census of 2000, there were 808 people, 362 households, and 205 families residing in the city. The population density was 894.4 people per square mile . There were 441 housing units at an average density of 488.1 per square mile...

, and Burt. It is joined by Cedar Creek

Cedar Creek (North Dakota)

Cedar Creek is a tributary of the Cannonball River in southwestern North Dakota in the United States.It rises near White Butte, south of Amidon in the badlands of Slope County...

 approximately 15 mi (24 km) southwest of Shields

Shields, North Dakota

Shields is an unincorporated community in Grant County, North Dakota, United States. Founded by Nathaniel J. Shields and his wife Mary and their four children in 1896. Shields' population peaked in 1920 with 250 people. Its elevation is 1,808 feet...

 and flows northeast, past Shields, forming the northern border of Sioux County

Sioux County, North Dakota

-Demographics:As of the census of 2000, there were 4,044 people, 1,095 households, and 871 families residing in the county. The population density was 4 people per square mile . There were 1,216 housing units at an average density of 1 per square mile...

 and the Standing Rock Indian Reservation

Standing Rock Indian Reservation

The Standing Rock Indian Reservation is a Lakota, Yanktonai and Dakota Indian reservation in North Dakota and South Dakota in the United States...

. It joins the Missouri in Lake Oahe

Lake Oahe

Lake Oahe is a large reservoir behind Oahe Dam on the Missouri River beginning in central South Dakota and continuing north into North Dakota in the United States. The lake has an area of and a maximum depth of . By volume, it is the fourth-largest reservoir in the US. Lake Oahe has a length of...

 near Cannon Ball

Cannon Ball, North Dakota

Cannon Ball is a census-designated place in Sioux County, North Dakota in the United States and on the Standing Rock Indian Reservation. It sits in the northeastern part of Sioux County where the Cannonball River meets Lake Oahe of the Missouri River...

. The cannonball concretions found in the vicinity of this river are the source of its name.