<P> Heading north from Burlington, however, along the east side of Lake Champlain, I - 89 runs through the valley's northernmost stretches to the Canada--US border, where it becomes Quebec Route 133 and Autoroute 35, which trace the route of the Richelieu River in its southern section, where the Great Valley finally dissipates into the plain of the Saint Lawrence River to the east of Montreal . (The Richelieu River continues northward across the plain and empties into the Saint Lawrence to the northeast of Montreal .) </P> <P> The Great Valley, especially the southern - middle portion, is within the region known as Appalachia . </P>

Using the map key which part of the great appalachian valley is the arrow pointing to