(a) It is lawful for any two (2) or more counties separated by a stream, navigable or unnavigable, to unite in the erection, establishment, and operation of a ferry over the stream, each of the counties, if not more than two (2), paying one half (½) of all the expenses incurred in the erection and maintenance.
(b) If more than two (2) counties combine in the improvement and work, each shall pay an equal part of the expense, or they may meet the expense under terms they may provide by contract.