The James River provides the main drainage between two plateau regions, the large plateau on the eastern side and which other plateau?
James River (Dakotas): The James River (also known as the Jim River or the Dakota River) is a tributary of the Missouri River, approximately 710 miles (1,140 km) long, draining an area of 20,653 square miles (53,490 km) in the U.S. states of North Dakota and South Dakota.
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