Clearwater River, the name of several North American rivers. The Idaho Clearwater is a tributary of the Snake River. The North, Middle, and South forks, which total 200 miles (320 km) in length, lie entirely in Idaho. The Clearwater joins the Snake at Lewiston, on the Washington border.
There are two Clearwater rivers in Minnesota. One rises in Clearwater County and flows 205 miles (330 km) east and north to the Red Lake River. The second, only 20 miles (32 km) long, is in the south-central part of the state, flowing into the Mississippi at Clearwater.
The two Canadian Clearwater rivers both flow through Alberta. One is 230 miles (370 km) long and flows into the Athabasca River. It has numerous rapids. The other rises in the Rockies in Banff National Park and flows 130 miles (210 km) in a winding, generally northeastward, course to join the North Saskatchewan River.