 The last of the historic bridges along a former segment of US 2 is the structure carrying Ashmun Street ( BS I ‑ 75 ) over the Power Canal in Sault Ste . Marie . Built in 1934 , it is one of only three steel arch bridges in the state . The 42 @-@ foot @-@ wide ( 13 m ) and 257 @-@ foot @-@ long ( 78 m ) structure is described by MDOT as " massive " with an " innovative " construction method : the previous structure was used as a falsework for the current bridge before removal . 
