Aroostook

County, northern Maine, U.S. It is bordered by Quebec, Can., to the west and northwest and by New Brunswick, Can., to the north and east. The northern boundary is defined by the St. Francis and St. John rivers. The county is a hilly highland region with numerous streams and lakes. Major waterways include the Allagash, Aroostook, Big Black, Little Madawaska, Machias, and Mattawamkeag