In Acadia National Park near Bar Harbor, Maine, the National Parks Service just completed flossing “Mr. Rockefeller’s teeth,” the nickname given to the large chunks of granite edging roads built by John D. Rockfeller Jr. The “teeth” were in desperate need of a cleaning to remove vegetation that had grown between the boulders since the NPS took over the roads in 1960.

The cleaning is part of a $6 million renovation effort to return the 70 km of gravel roads to full use by hikers, bikers and horse-drawn carriages visiting Acadia’s 16,000 hectares of park land.

Over 3 million people a year visit Acadia, America’s oldest national park east of the Mississippi River. While the park doesn’t offer the dramatic vistas and natural wonders of sites such as Yosemite and Yellowstone parks, it does offer rich forests, low peaks with clear visas, sparkling clean lakes and kilometers of granite coast where the fight between sea and land seems especially clear and fierce. There is also abundant wildlife in the peak and the surrounding waters.

Most of the park lies on Desert Island (pronounced “duh-ZURT”). Glaciers 1,000 to 3,000 meters thick formed the island, scouring and gouging out hills and valleys to create Jordan and Long ponds, Echo and Eagle lakes and beautiful fjordlike Sommes Sound. The most recent glacier began retreating about 18,000 years ago, leaving behind huge granite boulders called erratics on the summit of the park’s high point, 465-meter Mount Cadillac.

Today the ocean is the main agent of change here, pounding the granite face of Otter Cliffs, smoothing the pink and gray cobblestones at Little Hunter Beach and grinding ever finer the sand at the park’s only sand beach, Newport Cove.

Mount Desert was the summer home to the Wabanaki Indians when the French explorer Samuel Champlain visited in 1604. The French and English struggled for control of it until the English finally prevailed in 1759.

It was only another 100 years before traditional industries like farming, fishing and boat building began to fade and tourism began to rise. By 1880, 30 hotels crammed nearby Bar Harbor.

The tycoons of America’s industrialization (sometimes termed robber barons) — the Rockefellers, Vanderbilts, Fords, Astors, Morgans and Pulitzers, to name a few — all built “summer cottages” here. In fact, these “cottages” are actually homes of palatial dimensions on the island’s sheltered coast.

When development, including logging, threatened their rustic retreats, they banded together to form a public land trust in 1901 with Charles W. Eliot, president of Harvard University, at its head. The trust appointed George Bucknam Dorr, heir to a textile fortune, as its director. He worked tirelessly to enlarge the trust’s land holdings, often using his own fortune to do it.

In 1919 the 6,000 hectares within the trust became America’s first park east of the Mississippi. It was named Lafayette National Park, and Dorr held the post of superintendent until his death in 1943.

Under his tenure the park doubled in size. The donation of the 800-hectare Schoodic Peninsula had just one small problem: The English owners objected to the park’s Francophile name. Dorr arranged an act of Congress to change the park’s name to Acadia and Schoodic Peninsula was duly donated.

Although John D. Rockefeller Jr. donated 4,000 hectares himself, he is more remembered for his carriage roads. In 1913, concerned at the ever-growing rate of automobile encroachment, he started construction on a system of gravel roads strictly for use by horse, bike and hiker, complete with 17 carefully crafted granite and cobblestone bridges. These days wintertime cross-country skiers also make good use of his contribution.

Even if you have no intention of setting foot, hoof or tire on the carriage roads, Acadia has plenty to see and do. The Hulls Cove Visitor Center offers a background film, a large map, plenty of literature and the chance to sign up for bird walks, shoreline discovery walks and other activities led by park rangers.

All of the park’s main points, including Mount Cadillac’s peak, are accessible by car. At Ship Harbor, as at many places, the NPS leaves pamphlets for tourists to use on self-guided tours. The gentle 2.4-km loop leads past deserted apple orchards through groves of red spruce inhabited by finches and nuthatches. Closer to the shore, white spruce take over and huge pink granite slabs form tidal pools full of sea weed, crabs, starfish, barnacles, periwinkles and more. The return loop leads past the estuary that gives Ship Harbor its name, with a sea depth that varies with the tides from 24 cm to 240 cm.

Almost 200 km of hiking trails crisscross the park, all of them well marked and graded according to difficulty. Some are gentle strolls through meadows, others are gentle climbs that reward with views that take in both fresh and salt water. Among the most strenuous is the Beehive, a half-hour scramble up pink granite boulders sometimes using iron ladders drilled into particularly steep rock faces. The reward here (beside a stupendous view) is a great feeling of relief and accomplishment.

After a hard (or relaxing) morning at the park wander over to Jordan Pond and its restaurant, justly famed for its afternoon tea and fruit turnovers as well as its view across the pond of two rounded mountains called “the Bubbles.”

Then it’s off again, perhaps for a swim at Newport Cove; but with the water temperature around 13 C, most swims are pretty short. Alternately, go listen to the ocean roar into the narrow channel aptly named Thunder Hole. Or take a leisurely bike ride on the carriage roads.

Although the Rockefellers and other robber barons of America’s boom are typically remembered for their notoriety, this is one instance where they have left the public with a lasting and meaningful legacy.

For summer-season visits, reserve five months in advance. In Bar Harbor several companies rent gear reasonably for everything from hiking to kayaking.

In line with COVID-19 guidelines, the government is strongly requesting that residents and visitors exercise caution if they choose to visit bars, restaurants, music venues and other public spaces.