Mount Desert Island

Mount Desert Island: Heart of Acadia National Park

Mount Desert Island, often called MDI, is one of the most iconic and beloved coastal destinations in the United States. As the largest island off the coast of Maine and the home of Acadia National Park, it offers a rare blend of rugged mountains, quiet harbors, dramatic shorelines, and charming New England towns. 

Visitors come from around the world to explore its landscapes, walk its historic carriage roads, and experience the unique meeting point of forest, granite, and the Atlantic Ocean. Mount Desert Island is not just a gateway to Acadia—it is the essence of Acadia’s beauty.

Mount Desert Island

Quick Reference: Mount Desert Island (MDI)

Feature	Details
Location	Off the coast of Maine, part of Hancock County
Size	About 108 square miles, the largest island off the Maine coast
Park Presence	Home to the majority of Acadia National Park
Major Towns	Bar Harbor, Southwest Harbor, Northeast Harbor, Tremont
Highest Point	Cadillac Mountain, 1,530 ft – highest peak on the U.S. Atlantic coastline
Geographic Makeup	Rugged granite mountains, coastal cliffs, lakes, ponds, and dense forests
Shoreline	Over 100 miles of rocky and sandy coastline
Main Access Points	Bar Harbor (primary), Trenton Bridge, Otter Creek, Seal Harbor
Popular Attractions	Cadillac Mountain, Jordan Pond, Sand Beach, Thunder Hole, Otter Cliff, Carriage Roads
Transportation	Park Loop Road, Island Explorer bus (seasonal), scenic drives and ferry connections
Primary Activities	Hiking, biking, wildlife watching, kayaking, scenic drives, tidepooling
Unique Features	Glacially carved landscapes, fjard (Somes Sound), historic carriage roads

Where Is Mount Desert Island?

Mount Desert Island is located on the northeastern coast of Maine, in Hancock County. Spanning approximately 108 square miles (280 km²), making it the second-largest island on the eastern seaboard of the United States. The island is connected to the mainland by a short bridge via Route 3 at the town of Trenton, making it easily accessible by car.

History and Cultural Significance

Mount Desert Island has a rich history that dates back thousands of years. The Wabanaki people, Native Americans who have lived in the region for at least 12,000 years, called the island “Pemetic,” meaning “the land of the mountains.” They hunted, fished, and gathered food in the area, living in harmony with its ecosystems.

The island was first documented by Europeans in 1604, when French explorer Samuel de Champlain sailed into the area and gave the island its current name, "Île des Monts Déserts," which translates to "Island of Bare Mountains." This name was inspired by the island's rocky, barren mountaintops that contrast with its lush forests. Throughout the 18th and 19th centuries, European settlers arrived on the island, establishing small fishing and farming communities.

In the 19th century, artists from the Hudson River School popularized the area’s beauty through their paintings.

In the late 19th century, Mount Desert Island became a popular summer destination for wealthy families from the Northeast, including figures like John D. Rockefeller, J.P. Morgan, and the Astor family. These "rusticators," as they were called, built grand summer estates and helped preserve much of the island's natural beauty. Their influence led to the establishment of Acadia National Park in 1916, making it the first national park east of the Mississippi River.

A Land of Contrasts and Natural Splendor

MDI’s landscape is one of the most diverse and dramatic on the Atlantic seaboard. It boasts towering granite peaks, dense forests, serene ponds, sandy beaches, and rocky coastlines that face the turbulent Atlantic Ocean. Much of this beauty is protected within Acadia National Park, which occupies about half of the island.

1. The Mountains:

The island's interior is dominated by a range of rounded granite mountains. The tallest, Cadillac Mountain (1,530 feet), is the highest point along the North Atlantic coast and famous for being the first place in the U.S. to see sunrise during part of the year. Other notable peaks include Dorr Mountain, Pemetic Mountain, and Sargent Mountain, each offering panoramic views and challenging trails.

2. The Coastline:

Mount Desert Island’s shoreline alternates between steep pink granite cliffs and quiet coves. Along the Park Loop Road, visitors encounter iconic coastal landmarks like Sand Beach, Thunder Hole, and Otter Cliffs, each showcasing the island’s rugged maritime charm.

Towns on Mount Desert Island

Mount Desert Island is home to several charming towns and villages, each with its own character and offerings.

1. Bar Harbor:

The most popular town on the island, Bar Harbor is the main hub for tourism and the closest community to Acadia National Park. Known for its walkable downtown, lively waterfront, great restaurants, and access to boat tours and hiking trails, Bar Harbor is the perfect base for visitors exploring the island.

2. Mount Desert:

The town of Mount Desert includes several quiet villages like Northeast Harbor and Seal Harbor, known for their upscale homes, harbors filled with yachts, and peaceful, uncrowded beauty. This side of the island is a favorite for those seeking tranquility.

3. Southwest Harbor:

Located on the "quiet side" of the island, Southwest Harbor offers a more laid-back atmosphere. It’s home to shops, galleries, and boatyards, as well as the Wendell Gilley Museum. It’s also a gateway to trails on the western side of Acadia, such as Beech Mountain and St. Sauveur Mountain.

4. Tremont:

Tremont includes small communities like Bass Harbor, famous for the Bass Harbor Head Lighthouse, one of the most photographed spots in Maine. This is another excellent location to enjoy the quieter side of Mount Desert Island.

Carriage Roads and Historic Bridges

One of the most iconic features of Mount Desert Island is its network of historic carriage roads. Built between 1913 and 1940 by John D. Rockefeller Jr., these roads were designed for horse-drawn carriages and wind gracefully through forests, around mountains, and over stone bridges. Made with local materials and carefully integrated into the landscape, the carriage roads remain one of the island’s most charming and beloved attractions. Today, they are used by walkers, cyclists, joggers, and equestrians.

Lakes, Ponds, and Freshwater Wonders

MDI is home to more than two dozen named ponds and lakes, many of which supply the island’s drinking water or provide serene escapes for kayakers and hikers. Jordan Pond and Eagle Lake are the most famous, surrounded by mountains and connected by winding carriage paths. Smaller ponds—such as Bubble Pond, Upper and Lower Hadlock Ponds, and Long Pond—offer tranquility and excellent opportunities for paddling and wildlife watching. These freshwater bodies are essential parts of the island’s natural balance.

Ecology and Wildlife

The island’s diverse ecosystems are home to a wide variety of plant and animal species. Mount Desert Island’s forests consist primarily of spruce, fir, and pine, as well as hardwoods like maple, oak, and birch. The island’s many wetlands, streams, and ponds support species such as beavers, otters, and amphibians. The island is also an important stopover for migratory birds, with species like warblers, peregrine falcons, and bald eagles frequently seen in the area.

Marine life is abundant in the waters surrounding the island, with seals, porpoises, and a variety of fish species calling the area home. Frenchman Bay, in particular, is a popular location for observing whales, with humpback, finback, and minke whales often sighted during the summer months.

Recreation and Tourism

Mount Desert Island is a haven for outdoor enthusiasts. In addition to the extensive hiking opportunities provided by Acadia National Park, visitors can enjoy a range of activities such as cycling, rock climbing, and horseback riding. The island's lakes and ponds, including the pristine Jordan Pond and Eagle Lake, offer opportunities for swimming, kayaking, and canoeing. The surrounding waters are popular for sailing and fishing, with lobster fishing being an iconic activity in the region.

For those interested in more leisurely pursuits, the island’s villages offer a variety of cultural attractions, including art galleries, museums, and theaters. The Abbe Museum in Bar Harbor, for instance, is dedicated to preserving and sharing the history of the Wabanaki people, while the Islesford Historical Museum on Little Cranberry Island offers a glimpse into the island’s maritime past.