Federal law says any state proposing to demolish an historic bridge must “first make the historic bridge available for donation to a State, locality, or responsible private entity.” Some of the available bridges are listed or eligible for listing on the National Register of Historic Places and are covered by various preservation covenants. Bridge ownership will be transferred to the new owner who assumes all legal and financial responsibility for the structure. New owners will need to make sure their proposal will allow their bridge of choice to either be made usable or relocated to a suitable location.
Federal funding through programs such as Transportation Alternatives Program (TAP) or Recreation Trails Program (RTP) are available. Up to 80 precent of the demolition costs (what would have been spent to demolish the bridges) is potentially available to reimburse recipients for reusing them. This funding is primarily available if the recipient is removing the bridge from its current location themselves.
If you are interested in owning one of Missouri's historic bridges you should be aware that “Buy America” provisions of Federal grants will apply.
MoDOT offers these links for more information:
FHWA Reasonable Costs Associated With the Demolition of Historic Bridges