Motor Roads

a B&W photo showing a group on horse drawn buckboard carriage in front of the ocean
From July 12 to July 24, 1888 a party of twenty young people who attended Westtown [Quaker] School vacationed on Mount Desert Island. Here in the Tenth Day Chapter, written by Anna Helena Goodwin, the young people, aboard a buckboard, passed Sand Beach on July 21, 1888. Photo Credit: Southwest Harbo

From Paths to Roads

Although present-day visitors traditionally drive to the top of Cadillac Mountain before dawn to witness the first sunlight striking the American continent, the roads of Mount Desert Island were not always so accommodating. Since time immemorial, Wabanaki people traveled throughout the island using a sophisticated network of footpaths. When European colonists arrived in 1761, they too used these paths, widening many to make room for horses and buckboard wagons. The trail to the top of Cadillac Mountain, for instance, was widened and made a toll road during the 1850s. Early European settlers to Mount Desert Island quickly began constructing their own roads in order to enhance economic and social interaction. As early as 1777, residents had connected the island communities of Bar, Bass, and Southwest harbors with crude roads that were often impassable during inclement weather.


Early Pressure on Roads and the 'Auto Wars'

Over time, a network of roads across Mount Desert Island and the Schoodic Penninsula began to modernize. Increases in tourism and the rise of the automobile during the final decades of the nineteenth century, led some residents promoted road construction as a means of drawing visitors to the island. In 1888, for example, locals built a road to the shore of Eagle Lake in an effort to promote the island as a vacation destination. Other islanders were less enthused and a time period known locally as the 'auto wars' ensued. In 1903, voters on Mount Desert Island voted to ban automobiles on the island and in 1909 the Maine state legislature banned automobiles from all Maine island roads. Over the years, many locals found creative ways to challenge the ban, even to the point of being arrested for 'coasting' their automobile down a hill instead of 'driving' it.

Summer resident John D. Rockefeller, Jr., whose family fortune resulted from the Standard Oil Company, ironically saw the increase in the number of cars as a threat to his idyllic island getaway. In reaction to this symbol of urban industrial society, he constructed carriage roads for horse and foot traffic only. By 1941 he had built more than forty miles of such roads throughout the east side of the island. The first roads were built on his Seal Harbor estate; later roads were constructed on park lands, or land which Mr. Rockefeller acquired and later turned over to the park.

Park founder, George B. Dorr, worked out a compromise that let some autos come to the island via some roads. Later, around 1911, Southwest Harbor was the first community on the island to vote to allow cars, with Bar Harbor following in 1913.
Historic photograph of motor road with cars lining edge
Cars along the motor road at Otter Cliffs, circa 1938

Courtesy National Park Service/Acadia National Park

Plans For Motor Roads

Acadia’s motor road system was constructed over a 36 year period. The planning and design were not without challenges resulting from a difficult topography, private and public land ownership, economic verses conservation interests, and the financial constraints brought on by the Great Depression and World War II.

Non-contiguous segments of the motor road system were built from 1922 to 1958, providing work for both locals and those in the Civilian Conservation Corps (CCC) during the 1930s and 1940s respectively. In total, the system was completed in eighteen different phases: sixteen of them on the eastern side of Mount Desert Island (twelve segments making up the Park Loop Road and four spurs that connect to it) and two segments making up the Schoodic Loop Road on Schoodic Peninsula.


From Vision to Reality

George Dorr, a central figure in the park’s establishment and its first superintendent, had a vision in 1922 for connecting the Eagle Lake and Jordan Pond areas and allowing access to reach Cadillac Mountain. John D. Rockefeller brought these ideas to fruition by personally funding most of the motor road projects, in addition to expanding access to the park on his famous carriage roads. Using his connections to leadership in the National Park Service and wealth to acquire and donate lands, Rockefeller played a critical role in setting a standard for roadways and landscapes in national parks.

Rockefeller planned for a "Park Loop Road" that would provide access for visitors around the island and show off the varied landscape of mountains and valleys carved by glaciers, in addition to the tremendous coastline. Construction begin in 1927 at the northern end of Eagle Lake to the Jordan Pond Tea House, and continued with small connecting road project for the next few decades.

Construction workers stand along the edge of a unpaved road
Local laborers and members of the CCC were critical in the construction and completion of motor roads across the park

Courtesy National Park Service/Acadia National Park

A Thoughtful Design

The motor roads were praised for their scenic quality and careful consideration of moving with the land, but local opposition still came from those who feared negative impacts to the area. Rockefeller's original hope for the Park Loop Road was ultimately altered by this community opposition, but the final segment was completed by the Bureau of Public Roads (BPR) in 1958.

The key to success in Acadia’s motor road system was collaboration between engineers, landscape architects, conservationists, local laborers, the NPS, and BPR. Engineers including Leo Grossman, Walters Hill, and Paul Simpson helped with projects including the Cadillac Mountain Road project and carriage roads. Benjamin Breeze and Charles Peterson, landscape architects with the NPS, and Frederick Law Olmsted, Jr. planned and designed several motor roads segments and other park projects. Hundreds of skilled laborers made up the crews assigned to construction projects across the park.

The completion of the motor road system, and the carriage road system and trail network, shows a level of skill, care, and passion from the various heads and hands involved—many of them nameless in our records. Their contributions can still be recognized today in the transportation network laid out for future generations of park visitors.

Drawing of motor road features with descriptions
Drawing of motor road development in various locations at Acadia National Park

Historic American Engineering Record, National Park Service, Harlen D. Groe, 1995


Construction and Features

The motor roads at Acadia were constructed with some distinct features:

  • All roads are surfaced in bituminous concrete and no grade exceeds seven percent.
  • Pavement widths average 18.7 feet and are typically wider at curves.

  • Spiral transitions and superelevations are employed as road construction techniques which widen and bank the curves and allow drivers to maintain speed and transition smoothly into the curves. The Cadillac Mountain Road is a good example of these techniques.

  • Structures along the motor roads include bridges, causeways, retaining walls, guard walls, and drainages.
  • Careful consideration was taken to either build or face these structures with native granite to aid visual integration with the surroundings.
  • Most of the twenty bridges along the motor roads are made with reinforced concrete, masonry parapet walls, facings, and ornamentation that matches style elsewhere in the park.
  • Guard walls along the motor roads systems are made of large stones or rectangular quarried blocks set three to five feet apart into the road shoulder.
Historic photograph of road construction on a mountain
View from Station 138 of road construction on Cadillac Mountain, circa 1930

Courtesy National Park Service/Acadia National Park

The roads intentionally move with the land, allowing for visitors to view and experience the landscape without sacrificing the topography. The motor road system was integrated with the carriage road system and hiking trails, creating a network for visitors to explore Acadia by car, foot, carriage, and later bicycle. Despite a long construction period, a consistent use of the Rustic Design is still visible today – where roads blend with natural features as much as possible. Much of the vegetation along the roads was destroyed in the Fire of 1947 but have since rebounded. These plants along the road shoulders and in wetlands, meadows, and forests continue to help blend the roads with the park’s landscape.

Bus and cars on a park road
Road traffic near Otter Cliffs on the Park Loop Road

Photo by Ashley L. Conti, Friends of Acadia, NPS

Maintenance and Future of Motor Roads

After Rockefeller’s death in 1960, the combination of lessened interest, limited staff, and shrinking budgets for maintenance meant motor roads and carriage roads feel into disrepair. With the assistance of special projects, volunteers, and donations by Friends of Acadia, the historic motor roads were rehabilitated and continue to be maintained – offering the same park driving tour experience intended by the visionaries, planners, engineers, and designers.

In recent years, transportation issues at the park have become more complex as Acadia's visitation increases. Traffic congestion from private vehicles, concessions buses, commercial tour coaches, public transportation shuttle buses, and bicycles creates public safety issues, impacts to the historic motor road system, and impacts to the park's natural and cultural resources.

In order to address the best way to provide efficient and safe transportation, high quality experiences for visitors, and ensure protection of park resources, the National Park Service began developing a transportation plan in 2015. After years of planning, public involvement, and revisions, the park released a Final Transportation Plan/Environmental Impact Statement in 2019. Full implementation of the plan may take a decade or more and initial work began in 2020 with the vehicle reservation system.



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    Last updated: November 1, 2023

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