Mount Desert Island in Hancock County, Maine, is the largest island off the coast of Maine. With an area of 108 square miles (280 km2) it is the 52nd-largest island in the United States, the sixth-largest island in the contiguous United States, and the second-largest island on the Eastern Seaboard, behind Long Island and ahead of Martha's Vineyard. According to the 2010 census, the island has a year-round population of 10,615. In 2017, an estimated 3.5 million tourists visited Acadia National Park on MDI. The island is home to numerous well-known summer colonies such as Northeast Harbor and Bar Harbor.

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.