List of longest rivers of the United States (by main stem)

The Mississippi drainage basin includes the Missouri and the Mississippi rivers, the two longest main-stem rivers in the United States, as well as 18 more of the rivers on this list. The Mississippi main stem is highlighted in dark blue.

The main stems of 38 rivers in the United States are at least 500 miles (800 km) long. The main stem is "the primary downstream segment of a river, as contrasted to its tributaries". The United States Geological Survey (USGS) defines a main-stem segment by listing coordinates for its two end points, called the source and the mouth. Well-known rivers like the Atchafalaya, Willamette, and Susquehanna are not included in this list because their main stems are shorter than 500 miles.

Seven rivers in this list cross or form international boundaries. Two—the Yukon and Columbia rivers—begin in Canada and flow into the United States. Three—the Milk and Saint Lawrence rivers and the Red River of the North—begin in the United States and flow into Canada. Of these, only the Milk River crosses the international border twice, leaving and then re-entering the United States. Two rivers, the Colorado and the Rio Grande, begin in the United States and flow into or form a border with Mexico. In addition, the drainage basins of the Mississippi and Missouri rivers extend into Canada, and the basin of the Gila River extends into Mexico.

Sources report hydrological quantities with varied precision. Biologist and author Ruth Patrick, describing a table of high-discharge U.S. rivers, wrote that data on discharge, drainage area, and length varied widely among authors whose works she consulted. "It seems," she said, "that the wisest course is to regard data tables such as the present one as showing the general ranks of rivers, and not to place too much importance on minor (10–20%) differences in figures."

Table

The primary source for watershed and discharge data in the table below is Rivers of North America. Conflicting data from other sources, if the difference is greater than 10 percent, is reported in the notes. Discharge refers to the flow at the mouth. In the "States, provinces, and image" column, the superscripts "s" and "m" indicate "source" and "mouth". Non-U.S. states appear in italics. Except in the "States, provinces, and image" column, abbreviations are as follows: "km" for "kilometer", "mi" for "mile", "s" for "second", "m" for "meter", and "ft" for "foot".

Key
River is not entirely within the United States.
Watershed is not entirely within the United States.

Longest main-stem rivers of the United States

#	Name	Mouth	Length	Source coordinates	Mouth coordinates	Watershed area	Discharge	States, provinces, and image
1	Missouri River	Mississippi River	2,341 mi 3,768 km			529,353 mi2 1,371,017 km2	69,100 ft3/s 1,956 m3/s	Montanas, North Dakota, South Dakota, Nebraska, Iowa, Kansas, Missourim
2	Mississippi River	Gulf of Mexico	2,202 mi 3,544 km			1,260,000 mi2 3,270,000 km2	650,000 ft3/s 18,400 m3/s	Minnesotas, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, Louisianam
3	Yukon River	Bering Sea	1,979 mi 3,185 km			324,000 mi2 839,200 km2	224,000 ft3/s 6,340 m3/s	British Columbias, Yukon Territory, Alaskam
4	Rio Grande	Gulf of Mexico	1,759 mi 2,830 km			340,000 mi2 870,000 km2	1,300 ft3/s 37 m3/s	Colorados, New Mexico, Texasm, Chihuahua, Coahuila, Nuevo León, Tamaulipasm
5	Colorado River	Gulf of California	1,450 mi 2,330 km			248,000 mi2 642,000 km2	1,400 ft3/s 40 m3/s	Colorados, Utah, Arizona, Nevada, California, Sonoram, Baja Californiam
6	Arkansas River	Mississippi River	1,443 mi 2,322 km			160,200 mi2 414,910 km2	35,500 ft3/s 1,004 m3/s	Colorados, Kansas, Oklahoma, Arkansasm
7	Columbia River	Pacific Ocean	1,243 mi 2,000 km			279,548 mi2 724,024 km2	273,000 ft3/s 7,730 m3/s	British Columbias, Washingtonm, Oregonm
8	Red River	Atchafalaya and Mississippi rivers	1,125 mi 1,811 km			65,590 mi2 169,890 km2	30,100 ft3/s 852 m3/s	Oklahomas, Texas, Arkansas, Louisianam
9	Snake River	Columbia River	1,040 mi 1,674 km			108,000 mi2 281,000 km2	55,300 ft3/s 1,565 m3/s	Wyomings, Idaho, Oregon, Washingtonm
10	Ohio River	Mississippi River	979 mi 1,575 km			204,000 mi2 529,000 km2	308,400 ft3/s 8,733 m3/s	Pennsylvanias, Ohio, West Virginia, Indiana, Illinois, Kentuckym 150px
11	Colorado River of Texas	Gulf of Mexico	970 mi 1,560 km			39,900 mi2 103,341 km2	2,600 ft3/s 75 m3/s	Texass, m
12	Tennessee River	Ohio River	935 mi 1,504 km			40,880 mi2 105,870 km2	71,000 ft3/s 2,000 m3/s	Tennessees, Alabama, Kentuckym
13	Canadian River	Arkansas River	906 mi 1,458 km			47,130 mi2 122,070 km2	6,100 ft3/s 174 m3/s	Colorados, New Mexico, Texas, Oklahomam
14	Brazos River	Gulf of Mexico	860 mi 1,390 km			44,620 mi2 115,566 km2	8,800 ft3/s 249 m3/s	Texass, m
15	Green River	Colorado River	760 mi 1,230 km			44,900 mi2 116,200 km2	6,100 ft3/s 172 m3/s	Wyomings, Colorado, Utahm
16	Pecos River	Rio Grande	730 mi 1,175 km			44,000 mi2 113,960 km2	71 ft3/s 2 m3/s	New Mexicos, Texasm
17	White River (Arkansas)	Mississippi River	720 mi 1,159 km			27,872 mi2 72,189 km2	34,600 ft3/s 979 m3/s	Arkansass, m, Missouri
18	James River	Missouri River	710 mi 1,140 km			20,942 mi2 54,240 km2	854 ft3/s 24.2 m3/s	North Dakotas, South Dakotam
19	Kuskokwim River	Bering Sea	702 mi 1,130 km			48,000 mi2 124,319 km2	67,000 ft3s 1,900 m3/s	Alaskas, m
20	Cimarron River	Arkansas River	698 mi 1,123 km			19,510 mi2 50,540 km2	1,500 ft3/s 42 m3/s	Oklahomas, m, Colorado, Kansas
21	Cumberland River	Ohio River	696 mi 1,120 km			17,930 mi2 46,430 km2	41,000 ft3/s 862 m3/s	Kentuckys, m, Tennessee
22	Yellowstone River	Missouri River	678 mi 1,091 km			70,400 mi2 182,336 km2	12,800 ft3/s 362 m3/s	Wyomings, Montana, North Dakotam
23	North Platte River	Platte River	665 mi 1,070 km			34,885 mi2 90,352 km2	770 ft3/s 21.9 m3/s	Colorados, Wyoming, Nebraskam
24	Milk River	Missouri River	625 mi 1,005 km			22,332 mi2 57,839 km2	670 ft3/s 18.9 m3/s	Alberta, Montanas, m
25	Ouachita River	Black River	605 mi 974 km			24,886 mi2 64,454 km2	29,800 ft3/s 843 m3/s	Arkansass, Louisianam
26	Saint Lawrence River	Gulf of Saint Lawrence	600 mi 965 km			620,000 mi2 1,600,000 km2	440,000 ft3/s 12,600 m3/s	New Yorks, Ontarios, Quebecm
27	Gila River	Colorado River	600 mi 960 km			57,850 mi2 149,832 km2	210 ft3/s 6 m3/s	New Mexicos, Arizonam
28	Sheyenne River	Red River of the North	591 mi 951 km			8,800 mi2 23,000 km2	288 ft3/s 8.2 m3/s	North Dakotas, m
29	Tanana River	Yukon River	584 mi 940 km			44,000 mi2 114,000 km2	41,800 ft3/s 1,185 m3/s	Alaskas, m
30	Smoky Hill River	Kansas River	576 mi 927 km			19,260 mi2 49,900 km2	1,542 ft3/s 43.7 m3/s	Colorados, Kansasm
31	Niobrara River	Missouri River	568 mi 914 km			12,600 mi2 32,600 km2	1,700 ft3/s 49 m3/s	Wyomings, Nebraskam
32	Little Missouri River	Missouri River	560 mi 900 km			8,310 mi2 21,500 km2	450 ft3/s 13 m3/s	Wyomings, Montana, South Dakota, North Dakotam
33	Sabine River	Gulf of Mexico	553 mi 890 km			9,756 mi2 25,268 km2	8,400 ft3/s 238 m3/s	Texass, Louisianam
34	Red River of the North	Lake Winnipeg	550 mi 890 km			111,000 mi2 287,500 km2	8,300 ft3/s 236 m3/s	North Dakotas, Minnesotas, Manitobam
35	Des Moines River	Mississippi River	525 mi 845 km			12,018 mi2 31,127 km2	6,400 ft3/s 182 m3/s	Minnesotas, Missouri, Iowam
36	White River (Missouri River)	Missouri River	506 mi 815 km			10,200 mi2 26,418 km2	570 ft3/s 16 m3/s	Nebraskas, South Dakotam
37	Trinity River	Galveston Bay	506 mi 815 km			17,970 mi2 46,540 km2	7,800 ft3/s 222 m3/s	Texass, m
38	Wabash River	Ohio River	503 mi 810 km			32,950 mi2 85,340 km2	1,001 ft3/s 28 m3/s	Ohios, Indianam, Illinoism

Map

Map of North America showing all rivers on this list

See also

• List of longest rivers in the United States by state

Notes and references

Notes

References

Works cited

• Benke, Arthur C., ed., and Cushing, Colbert E., ed. Rivers of North America. Burlington, Massachusetts: Elsevier Academic Press. ISBN 0-12-088253-1.