Plaque for West Portal of Tunnel: St. Clair Tunnel Constructed: 1888-1891, opened to traffic: September 19, 1891 with a faded photopgraph and all of its achievements including the first international sub-aqueous railway tunnel, and how the tunnel was electrified in 1908. It ends with 'The west portal is located six blocks east of this marker and can be seen by looking east along the railroad tracks at Sixteenth Street