Acadia National Park lies along the coast of Maine; accessible by vehicle, the park is approximately six hours north of Boston.Sea and mountain meet at Acadia; most of the park is located on Mount Desert Island, a mix of private property, parkland, and seaside villages that only in the summer are filled with residents.

Mount Desert Island was once a continental mainland, a granite rim on the edge of the ocean. Over 20,000 years ago, towering glacial ice sheets flowed over the mountains, widening valleys, rounding the mountain tops, and cutting passes. As the ice mass melted, the sea rose, causing floods for the valleys and the coast.

Samuel de Champlain, who explored the coast in 1604, called the island L'Isle des Monts Déserts, translated as "the island of infertile mountains." From his ship he probably could not see the mountains' forested slopes. Only later, in the mid-19th century, people rediscovered Mount Desert and they built cottages, anchored their yachts, and cherished its natural wildness. To protect it, people living on the island, donated the nucleus land for the park, the first east of the Mississippi. The original name, Lafayette National Park, was later changed. Dependent on donated land since its foundation, the park took what it could get, skirting around private property and slowly growing. Acadia's real estate was so patchy that only in 1986 the Congress was able to set its official boundaries.

Although Acadia National Park is one of the smaller national parks, it is one of the most visited; in fact, almost two and a half million people a year visit the park. The park can be visited all year-round, but the main visitor center is open from mid-April through the end of October. Heavy traffic is to be expected in July and August. Spectacular foliage attracts the crowd from September to the beginning of October. From December through mid-April most park roads are closed due to snow and ice; however, parts of the park are open for cross-country skiing.