You are in the CarrTracks website Picture Gallery.
This index begins in northern Illinois, north of Chicago and works its way south. Most of the pictures in this set can be found on disks 110, 111, and 113.
I also have an extensive collection of pictures of three
other interesting railroad operations in Illinois.
See the Crab, Orchard, and Eqyptian,
Chicago North Western Railway (includes Iowa),
or the Toledo Peoria and Western galleries for more pictures.