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. James River (Dakotas):  The river provides the main drainage of the flat lowland area of the Dakotas between the two plateau regions known as the Coteau du Missouri and the Coteau des Prairies.
i don't know