sentences:  US 11 and I-81 finally part ways at this point, with I-81 continuing north toward Canada and US 11 heading northeast to serve some of the North Country's northernmost communities.As the highway leaves the Watertown area, it passes into another area of rolling, open terrain with only pockets of development in the immediate vicinity of the road's interchanges.NY 37 largely replaces US 11 as the paralleling surface route, and the state route follows I-81 for to the vicinity of Theresa.