The Thompson River is the largest tributary of the
Grand River in the central
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
, flowing from southern
Iowa
Iowa () is a state in the Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wisconsin to the northeast, Illinois to the ...
into
Missouri
Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...
. In Iowa, it is known simply as the Grand River and passes near the city of
Grand River. The river is long,
[U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data]
The National Map
accessed May 26, 2011 and its
drainage basin
A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, t ...
is roughly , of which are in Missouri.
It rises in the agricultural lands of
Adair County, Iowa
Adair County is a county in the U.S. state of Iowa. As of the 2020 census, the population was 7,496. Its county seat is Greenfield.
History
Adair County was formed in 1851 from sections of Pottawattamie County. It was named for John Adair, ...
, a few miles northeast of
Greenfield. The river initially flows east then bends south, passing
Macksburg and
Davis City and crossing
Interstate 35
Interstate 35 (I-35) is a major Interstate Highway in the central United States. As with most primary Interstates that end in a five, it is a major cross-country, north–south route. It stretches from Laredo, Texas, near the Mexican border ...
. It then flows into Missouri, where much of its course is
channelized. The
Weldon River
Weldon River is stream in Clark and Decatur counties in southern Iowa and Grundy and Mercer counties in northern Missouri of the United States. It is a tributary of the Thompson River. The confluence is two miles northwest of Trenton. It has a ...
joins at the town of
Trenton, the largest settlement along the Thompson River. Below Trenton, the Thompson meanders south for another , joining the Grand River just north of
Utica in
Livingston County.
See also
*
List of rivers of Iowa
The following is a list of rivers and creeks in Iowa. The rivers are listed by multiple arrangements:
*those that form part of the boundaries of the U.S. state of Iowa;
*ordered by drainage basin, with tributaries indented under each larger rive ...
*
List of rivers of Missouri
List of rivers in Missouri (U.S. state).
By drainage basin
This list is arranged by drainage basin, with respective tributaries indented under each larger stream's name.
Mississippi River
Arkansas River
*Mississippi River
**Arkansas River (AR ...
References
Rivers of Iowa
Rivers of Missouri
Tributaries of the Missouri River
Bodies of water of Adair County, Iowa
Bodies of water of Decatur County, Iowa
Bodies of water of Madison County, Iowa
Rivers of Grundy County, Missouri
Rivers of Harrison County, Missouri
Rivers of Livingston County, Missouri
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