Saint Croix Island, long known to locals as Dochet Island, is a small uninhabited island in Maine near the mouth of the Saint Croix River that forms part of the Canada–United States border separating Maine from New Brunswick. The island is in the heart of the traditional lands of the Passamaquoddy people who, according to oral tradition, used it to store food away from the dangers of mainland animals. The island was the site of an early attempt at French colonization by Pierre Dugua, Sieur de Mons in 1604. In 1984 it was designated by the United States Congress as Saint Croix Island International Historic Site. There is no public access to the island, but there is a visitor contact station on the U.S. mainland and a display on the Canadian mainland opposite the island.

Maine is the easternmost state in the New England region of the Northeastern United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and northwest, respectively. Maine is the largest state in New England by total area. Of the 50 U.S. states, it is the 12th-smallest by area, the 9th-least populous, the 13th-least densely populated, and the most rural. Maine's capital is Augusta, and its most populous city is Portland, with a total population of 68,408, as of the 2020 census.