Boundary Peak (Maine)

This mountain, which has no formal name, is located on the United States-Canada border between boundary markers 445 and 446. It is the highest point on the border east of the Rocky Mountains.^[1] The southeast half is in Oxford County, Maine; the northwest half is in Le Granit Regional County Municipality, Québec, Canada.

The south and east sides of the mountain drain via streams into the Kennebago River, thence into Cupsuptic Lake, through a series of lakes into the Rapid River and Umbagog Lake, the source of the Androscoggin River, which drains into Merrymeeting Bay, the estuary of the Kennebec River, and thence into the Gulf of Maine. The north and west sides of the mountain drain into Ruisseau Clearwater, thence into the Rivière Arnold, and the Rivaux Araignées, into Lac Mégantic, thence into the Chaudière River, and Saint Lawrence River, which drains into the Gulf of St. Lawrence.