The Three Borders linkage area includes the ‘top’ of Maine and portions of western New Brunswick and eastern Quebec. It is key to regional connectivity, linking northern Maine and the rest of the Northern Appalachians to the southwest with the extensive forests of the Gaspé Peninsula to the north and New Brunswick to the east. The St. John River forms the majority of the border between Maine and Canada in this linkage area.
The Maine side is mostly forested, especially in the western and central portion of the linkage area. The eastern portion of the Maine side is characterized by more agriculture and settlements along the river. The Quebec portion is more heavily populated and fragmented by roads than the New Brunswick portion, but the great majority of forest land in the linkage area is actively managed.