ACADIA NATIONAL PARK – It was easy to see Tuesday why George B. Dorr, Charles W. Eliot and others felt it was important to preserve the beauty and public accessibility of Mount Desert Island.

The sun was shining, a cool ocean breeze blew beneath a spotless blue sky and rocky cliffs rose behind Sieur de Monts Spring as park officials and members of the public celebrated the 90th anniversary of the founding of what would become Acadia National Park.

Eliot and Dorr were instrumental in establishing the Sieur de Monts Spring National Monument in August 1916. Three years later, Congress designated the parcel of land as Acadia National Park, the first national park east of the Mississippi River.

“George B. Dorr certainly had a vision,” park Superintendent Sheridan Steele said at the event, held on a lawn next to the Sieur de Monts Spring visitor center.

Dorr, who later served as the park’s superintendent for 28 years and after whom the park’s Dorr Mountain is named, donated the 5,000 acres that President Woodrow Wilson designated as the national monument, Steele said.

Many people – from John D. Rockefeller Jr. to park staff to volunteers – have helped preserve and expand the park to its current size of more than 47,000 acres, he said.

“I believe that work has been vigorously carried forward,” Steele said.

John Courtin, president of Friends of Acadia, and others also spoke about the work of Dorr, Eliot, and other founders.

“It was an incredible summoning of human will,” Courtin said of the founders’ efforts. “The vision that the founders had is in great shape.”

Steele said there is still more work to be done, however. Congress set a limit in 1986 for how much more Acadia could grow, but there are several privately owned parcels of land within that limit that Acadia officials would like to add to the park’s territory.

Burnt Porcupine Island in Frenchman Bay, land around Northeast Creek, and a large piece of land on Schoodic Peninsula all are on Acadia’s radar screen for possible acquisition, he said.

With about 70 people watching, the superintendent also cut a yellow ribbon to ceremonially reopen the renovated land around the Sieur de Monts Spring’s visitor center. New paths have been paved, new vegetation planted, new underground utilities installed and a new coat of paint put on the building as part of the $250,000 project, he said.

The improvements were paid for with fee revenue collected from park visitors, the superintendent pointed out. Since 1996 Acadia has been permitted by the National Park Service to keep the majority of its fee revenue in order to pay help for certain improvement projects and programs such as the Island Explorer bus system.

“Most of the visitors like knowing their fees go to improvements at Acadia,” Steele said.