You are in the CarrTracks website Picture Gallery.
The C&NW was double tracked from Chicago to Council Bluffs by 1902, and had finished installing signals by 1908. In 1925 the C&NW completed the installation of GRS continuous cab signals on 488 miles of double track from Chicago to Council Bluffs.
California Junction, Iowa
South Bend, Indiana
There are a few more pictures in the Iowa and Illinois Galleries.