Owyhee River - Course

Course

The Owyhee River has its source in northeastern Nevada, in northern Elko County, approximately 50 miles (80 km) north of the city of Elko. It flows north along the east side of the Bull Run Mountains of Nevada, passing through Wild Horse Reservoir and then cutting northeast past the north end of the range. The river runs through the Humboldt National Forest, and then past the communities of Mountain City and Owyhee in the Duck Valley Indian Reservation. It then enters southwestern Idaho, flowing northwest for approximately 50 miles (80 km) across the southwest corner of the state through Owyhee County. It is then joined by the South Fork Owyhee River from the south, approximately 10 miles (16 km) east of the Oregon border. The main tributary of the South Fork is the Little Owyhee River.

The Owyhee River then enters extreme southeast Oregon in southern Malheur County, generally flowing north in a zigzag course west of the Idaho border. It merges with the West Little Owyhee River from the south, then receives the Middle Fork Owyhee River and North Fork Owyhee River from the east at a location known as "Three Forks". It then passes through the Owyhee Canyon between Big Grassy Mountain and Whitehouse Butte, then turns north, flowing east of Burns Junction and then west of the Mahogany Mountains. In this area the Owyhee River receives the tributaries of Jordan Creek, Rattlesnake Creek, and Crooked Creek.

The Owyhee River enters the Snake River from the west on the Oregon-Idaho border approximately 5 miles (8 km) south of Nyssa, Oregon and 2 miles (3 km) south of the mouth of the Boise River. The final stretch of the river, below Owyhee Dam, emerges from the Owyhee Plateau and enters the Snake River Plain.