Links marked with S or T include historical information on lost passenger Stations and interlocking Towers. Beyond the Chicago area, information on towers serving multiple railroads is generally not duplicated among branch lines.

This section is being expanded, to include additional lines further from Chicago. Pages for the added lines are marked with UC for Under Construction.

Former Chicago & North Western Railway

Main/commuter lines.

Kenosha Subdivision (Chicago to Milwaukee) ST

Harvard Subdivision (Chicago to Janesville) ST
McHenry Subdivision (Crystal Lake to Ringwood) S
(formerly Elgin to Williams Bay)

Geneva Subdivision (Chicago to Elburn) ST
Geneva Subdivision (Elburn to Clinton) ST

Freight/branch lines.

Milwaukee Subdivision (Proviso Yard to St. Francis) T
Milwaukee Subdivision (St. Francis to Butler) T

Belvidere Subdivision (West Chicago to Rockford) ST
(formerly West Chicago to Freeport)

Peoria Subdivision (Nelson to Peoria) T

Troy Grove Subdivision (De Kalb to Troy Grove) S
(formerly Belvidere to Spring Valley)

Rockwell Subdivision (Global One to Kedzie) T

Cragin Subdivision (Grayland to Mayfair) T
(formerly Harding Avenue to Mayfair)

Farm Subdivision (Kenosha to Bain) S
(formerly Kenosha to Rockford)

Beloit Branch (Clinton Jct. to Beloit) S

Former Chicago & Eastern Illinois Railroad

Villa Grove Subdivision (Chicago to Dolton) ST
Villa Grove Subdivision (Dolton to Woodland Jct.) ST
Villa Grove Subdivision (Woodland Jct. to Villa Grove) T
Pana Subdivision (Villa Grove to Lenox) UC
Salem Subdivision (Findlay Jct. to Salem) UC
Mt. Vernon Subdivision/Marion Subdivision (Salem to Metropolis) UC

Cissna Park Subdivision (Goodwine to Cissna Park) UC
(formerly Cissna Jct. to Cissna Park)

Former Missouri Pacific Railroad

Mt. Vernon Subdivision (Benton Jct. to Chap) UC

Former Alton Route/Gulf Mobile & Ohio Railroad

Joliet Subdivision (Joliet to Bloomington) ST
Pequot Subdivision (Joliet to Mazonia) T
Springfield Subdivision (Bloomington to Wann) T
Joint Line (Wann to St. Louis) UC

Abandoned Lines

C&NW Skokie Subdivision/Weber Subdivision ST
C&NW St. Charles Subdivision/Aurora Subdivision S
C&NW Beloit Subdivision S

Chicago Great Western (Chicago to Dubuque) ST

Alton Washington Branch (Dwight to Washington) ST
Alton P&N Branch (Peoria to Springfield) UC

C&EI Westville Subdivision (Danville to Villa Grove) UC

North Shore Line (Chicago to Milwaukee) T
Electric interurban railway listed only for completeness of its interlocking towers, at crossings with "steam" railroads including Chicago & North Western.