BAR HARBOR – Maine-based outdoors retailer L.L. Bean is making a new commitment of $1 million to Friends of Acadia in support of the Island Explorer bus system.

President and CEO Stephen Smith and Acadia National Park Superintendent Kevin Schneider will appear together for the formal announcement on Tuesday.

Since 1999, the fare-free bus system has carried more than 6 million passengers, reduced private vehicle trips by about 2 million, and reduced pollution on Mount Desert Island. With the new donation, L.L. Bean has now donated and pledged more than $4 million.

Schneider says the Island Explorer “dramatically improves visitors’ enjoyment of the park by providing convenient access to trailheads and prime destinations.”