So I went to Plan B to find the General Mills that Mark was referring to. Tracing the CGW route to the east from the bridge, it was severed by the DuPage airport. But an industrial spur was built to the south to connect it with the UP/C&NW mainline. (The C&NW merged with the CGW in 1969 and then C&NW tore up most of the CGW routes because they were redundant with the C&NW after trucks replaced the horse and wagon.)
Tracing the route west of the bridge finds the track ending at a big vacant lot.
While tracing the route west of the river, I did find the remnants of a couple of other rail served industries. You can see a little stretch of the north siding still peaking through the weeds on the right side of the image.
I checked out a 1939 aerial photo for the General Mills plant, but this whole area was