World Facts

The 10 Longest Rivers in Colorado

The Rio Grande is the longest river in the state of Colorado.

Colorado is the eighth largest American state which encompasses parts of the Southern Rocky Mountains, the Great Plains and Colorado Plateau. Colorado has over 253 crucial rivers, and this includes the 158 rivers which pass through the state. Some of these rivers like the Rio Grande are part of an international border (Mexico-United States border) while Colorado River acts as the boundary between Nevada and Arizona. The Rio Grande is the longest River in Colorado. Colorado has seventeen rivers which drain an area of over 3,900 square miles.

Colorado's Major Rivers

1) Rio Grande

The Rio Grande is one of the main rivers in northern Mexico and the southwestern parts of the United States. It originates from the base of Colorado's Canby Mountain and then flows into the Mexican Gulf. The 1,896-mile long Rio Grande forms a big part of the United States-Mexico boundary. It also serves as a natural boundary between the Mexican states (Chihuahua, Tamaulipas, Nuevo Leon, and Coahuila) and the state of Texas. A smaller stretch of the river serves as the border between New Mexico and Texas. The river drains an area of about 182,000 square miles.

2) Arkansas River

The 1,469-mile long Arkansas River is one of the main branches of River Mississippi. It originates from Arkansas River Valley and then stretches east to the Midwest before flowing south through Arkansas and Oklahoma. It is the second longest branch in the Missouri-Mississippi river system and the sixth-longest river in the country. The river’s watershed occupies an area of about 170,000 square miles, and it has a mean discharging rate of about 41,000 cubic feet per second.

3) Colorado River

Colorado River drains a significant arid watershed which includes parts of two Mexican and seven American states. The 1,450-mile long river is one of the critical rivers in northern Mexico and the southwestern United States. The river rises from the Rocky Mountains and then flows through the Grand Canyon to Mead Lake on the Nevada-Arizona boundary before turning towards the Mexico-United States border. Once in Mexico, it flows into the Colorado River Delta. The Colorado River and its branches supply water to about 40 million people.

4) Canadian River

Canadian River is one of the longest branches of Arkansas River which drains an area of approximately 47,700 square miles. The 906-mile long river originates from Colorado and then flows through Oklahoma, Texas, and New Mexico. It is a slow-moving stream which is bounded by quicksand and red mud flats. According to Muriel Wright, the French Traders named the river back in 1820, when they saw a group of Canadian traders camped near its confluence.

5) Green River

Green River is the main branch of River Colorado. The Green River’s watershed occupies parts of Colorado, Utah, and Wyoming. The 730-mile long river originates from Wind River Mountains and then flows through Utah and Wyoming into River Colorado. It flows through some of the unique Canyons in the country and Colorado Plateau. The average flow rate of the Green River is about 6,121 cubic feet per second.

Other Rivers in Colorado

The top ten longest rivers in Colorado are over 383 miles long with San Juan River being the tenth. The 716-mile long North Platte River is one of the main branches of Platte River. The 698-mile long Cimarron River stretches across Kansas, Colorado, Oklahoma and New Mexico while the 575-mile long Smoky Hill River flows through Kansas and Colorado. The South Platte River is one of the main branches of Platte River which flows through Nebraska and Colorado.

The Longest Rivers in Colorado

RankRiverLength (miles)Length (km)
1Rio Grande1,8963,051
2Arkansas River 1,4692,364
3Colorado River1,4502,330
4Canadian River9061,458
5Green River7301,170
6North Platte River7161,152
7Cimarron River 6981,123
8Smoky Hill River560900
9South Platte River 439707
10San Juan River383616

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