Whenever the board of county commissioners of any county determines that the construction or maintenance of a ferry in a state adjoining such county or connecting such county with the adjoining state is of necessity or convenience to the citizens of the county, the board may enter into a contract for the construction or maintenance of such ferry, or make such contribution as may be deemed advisable toward the construction or maintenance thereof, and may lease, or grant exclusive permits to use, any wharf or landing owned or leased by the board to any person, firm or corporation furnishing, or agreeing to furnish, ferry service between such county and the adjoining state.