This image shows the small car and passenger ferry known as the Voyageur, after the French name for the early explorers of this region.
The description states:
The Voyageur, car & passenger ferry operating from Washington Island and the mainland. Door County, Wis.
–Another view of this vessel is seen here. Such vessels were essential to moving residents and visitors along with supplies to some of the nearby inhabited islands. Some still operate, others have closed with the construction of bridges where economically practical or when islands were abandoned.
This card is dated 1961.