Yampa River, CO

The Yampa River is a tributary of the Green River, approximately 250 mi (402 km) long, in the U.S. state of Colorado. The Yampa is the 2nd largest watershed in the State of Colorado.

It rises in the Flat Tops in northwestern Colorado, in the Routt National Forest in southeastern Garfield County, and flows northwest, past Yampa, and north to Steamboat Springs, where it turns abruptly west. It then receives its chief tributary, the Elk River, near the small town of Milner. It continues west in the plateau region along the north side of the Williams Fork Mountains, past the town of Craig. It is joined by the Little Snake River in Moffat County, just east of Dinosaur National Monument. Inside Dinosaur National Monument, it joins the Green near the border with Utah.

The Yampa forms a noticeably wide, shallow stream throughout much of its course. The lower three fourths of the Yampa, from the Elk river down, are navigable by small craft. However the meandering, shallow nature of the river can render the river unnavigable during late summer in low water years. The discharge of the Yampa varies from about 600 ft³/s (17 m³/s) during low water summers to 20,000 ft³/s (600 m³/s) in spring runoff. Average flow at its confluence with the Green is about 2500 ft³/s (71 m³/s).