 Another abandoned bridge is now privately owned and in use at the mouth of the Backwater Creek on the Keweenaw Bay near L 'Anse . The span was constructed in 1918 for $ 4 @,@ 536 ( equivalent to $ 345 @,@ 451 in 2015 ) . It is an 80 @-@ foot ( 24 m ) Warren truss design now situated on private property . This abandoned bridge was listed on the National Register in 1999 . 
