This is not the Canadian National bridge; the through-truss bridge shown here originally belonged to the Chicago, Burlington & Quincy (later, Burlington Northern). It is currently owned by the Illinois Railway and also used by Canadian PACIFIC's Dakota, Minnesota & Eastern Railraod. This bridge is slated to be closed to rail traffic in 2012, with trains being rerouted around it on the Illinois Central (now CNRR) bridge a short distance to the south.
Side note: The CB&Q through-truss bridge shown here replaced a covered bridge, probably in the late 1800s. Covered railroad bridges were extremely rare in the Midwest.