Question: The James River provides the main drainage between two plateau regions, the large plateau on the eastern side and which other plateau?
Sentence (from "Boundary Ranges"): They begin at the Nass River, near the southern end of the Alaska Panhandle in the Canadian province of British Columbia and run to the Kelsall River, near the Chilkoot Pass, beyond which are the Alsek Ranges of the Saint Elias Mountains, and northwards into the Yukon Territory flanking the west side of the Yukon River drainage as far as Champagne Pass, north of which being the Yukon Ranges.
Relevant evidence: No