🔒Acadia’s seasonal shuttle ridership jumps 20% amid expanded service

The free shuttle bus system that serves Acadia National Park and surrounding towns saw a 20.8% leap in passenger numbers in the three months the service has been operating so far this year.

The increase was driven in large part by the Island Explorer’s expanded service on two routes that began a month earlier than usual, on May 20, to coincide with the opening of the new Acadia Gateway Center in Trenton.

In July alone, ridership increased 6% year-over-year, even as park visitation remained flat.

But the increases won’t necessarily carry through the season, Paul Murphy, executive director of Downeast Transportation, Inc., told Mainebiz.

“We’re almost at capacity and, on busy days at busy times, we’re beyond capacity, so growth becomes more difficult once you’re carrying those kinds of numbers consistently,” he said. “We’ll see.”

Explorer numbers

Initiated in 1999, the seasonal Explorer carries passengers through Acadia and the surrounding gateway communities on Mount Desert Island and the Schoodic Peninsula. Since its inception, the system has eliminated millions of private vehicle trips in the park.

The propane-powered bus system carried its 10 millionth passenger in 2024. Service is offered seven days a week through mid-October, with reduced fall service beginning mid-August.

Typically, Explorer service starts in the park’s Schoodic Peninsula district just before Memorial Day. Full service in the Mount Desert Island district starts in late June.

This year, the MDI service started on May 20 at the gateway center with two routes going to Bar Harbor and to Acadia’s Park Loop Road. The date, which was five days before Memorial Day, coincided with the gateway center’s opening,

The 20.8% jump in ridership was almost entirely due to the additional service, said Murphy.

“July was a busy month as well,” he noted.

Still, overall ridership has yet to get back to pre-pandemic levels. In 2019, the number reached nearly 650,000. In 2025, the system carried about 506,000.

The nonprofit Downeast Transportation operates the Island Explorer in the park under a cooperative agreement with the National Park Service, which provides 72% of its operating expenses from park entrance pass revenues.

Gateway center opening

The gateway center had a soft opening in September 2025 and officially opened this past May. The intermodal transit and welcome center sits between Ellsworth and Mount Desert Island to attract visitors traveling south on Route 3 before arriving on Mount Desert Island.

The center serves as a hub for Island Explorer buses and commercial tour operators and has visitor amenities, park and regional tourism information, 300 free day-use parking spaces, 18 electric vehicle charging stations and 10 oversized vehicle spaces.

Fleet expansion

As Explorer passenger numbers expand, a plan is in the works to grow the fleet from 34 to at least 40 buses.

In 2024, the Maine Department of Transportation received a $23.5 million federal grant, supported in part by a $300,000 matching pledge from Friends of Acadia.

The money will fund the eventual replacement of existing buses and acquisition of new ones, said Murphy. It’s expected there will be two rounds of orders, the first for 23 buses and the second for 17. Maine's transportation department is working on bid specifications to find a manufacturer.

“We expect an order to be placed by year’s end,” said Murphy.

Park visits

In July, Acadia National Park counted 796,941 visitors to all three of its districts — Mount Desert Island, Schoodic Peninsula and Isle au Haut. That was down just slightly from a year ago, with 797,030 visitors.

The year-to-date number had a bit more of a decline. So far this year, 1,870,617 have visited the park, compared with 1,896,341 by the end of July last year.