Major River Basins

Colorado is the “headwaters” state for much of the western and central United States. That means that most of its rivers begin in the Rocky Mountains and flow across state lines. Four of the nation’s major rivers originate in Colorado: the Arkansas, Colorado, Platte, and the Rio Grande. Only the Green River, the Little Snake River, and Costilla Creek flow into the state, and then only for short stretches.

Rivers are the predominant water source for Coloradans. This water is highly prized because it starts as pristine high-quality snowmelt, not yet used and reused by others. Other states are not so fortunate.

Colorado has nine major river basins, which include the Arkansas, Colorado, Gunnison, North Platte, Republican, Rio Grande, South Platte, Dolores/San Juan/San Miguel, and the Yampa/White/Green. Each basin relies on a mixture of rain, snow and groundwater to fill its rivers and creeks. Likewise, each basin hosts a distinct range of water uses that help shape Colorado’s overall identity.

Learn more about Colorado’s nine unique river basins, where the water flows from the headwaters to the state line, how the water is stored and used, and what compacts govern the use of each basin.

Read about each of Colorado’s river basins:

Arkansas River Basin

Colorado River Basin

Dolores/San Juan/ San Miguel Basin

Gunnison River Basin

North Platte River Basin

Republican River Basin

Rio Grande Basin

South Platte River Basin

Yampa/White/Green River Basins