Bridge was indeed former Big Four (CCC&stL), then New York Central, Penn Central and was likely last used by Conrail (1976-1998). The bridge was reportedly built in 1902, after flooding destroyed both Big Four Bridges in the area.
Looks like maybe some of the old riveted stringer girders were used to block the end(s) of the bridge off too.
Agreed with previous comment. Bridge is very clearly a former railroad bridge.
Another mistaken identity.
This bridge is actually the former Big4 (NYC) bridge over Woodriver Creek that was part of that railroads Alton Branch from the Wye Track at East Alton off the Big4 (NYC) Old Line
to the Alton Union Station located on the riverfront near the former Lincoln-Douglas Square. At one time in the early 1900's
before the St. Louis Worlds Fair the Big4 ran commuter trains from Alton Union Station to East Alton to connect with their then mainline trains to St. Louis. The new High Line from Mitchell, Il to Hillsboro, IL rendered the line through East Alton as a secondary branch about 1912 and it was renamed the Old Line before being abandon before the Penn Central merger about 1960.
This line also connected to the Alton Joint Levee Tracks that were shared by all the downtown Alton railroads to reach the steamboat landing on the levee and to switch the Alton flour mills.
Robert F. Schramm