This report presents a case study of the partnerships that supported the implementation of the Island Explorer Shuttle Bus System, which was designed to respond to growing traffic congestion both in Maine's Acadia National Park and in the adjacent towns on Mount Desert Island, especially Bar Harbor. The system, which began operating in 1999 with six buses, is now comprised of 17 shuttle buses that in 2001 carried nearly 240,000 passengers. The Island Explorer is one of the most successful recent ATS within NPS.