Chicago & North Western had numbered subdivisions until the late 1950's, then named districts briefly, and since the 1960's had named subdivisions. Many subdivisions were combined or split over the years. Sold and abandoned subdivisions are generally identified by names which were in use the longest. In 1995 Chicago & North Western became part of Union Pacific, which continues to use named subdivisions. Many segments have been abandoned, or sold to other railroads.
Geneva Subdivision (Chicago-Elburn)
Geneva Subdivision (Elburn-Clinton)
Belvidere Subdivision (West Chicago-Rockford-Freeport)
McHenry Subdivision (Elgin-Crystal Lake-Ringwood-Williams Bay)
Troy Grove Subdivision (Belvidere-De Kalb-Troy Grove-Spring Valley)
Rockwell Subdivision (Global One-Kedzie)
Cragin Subdivision (Harding Avenue-Grayland-Mayfair)
Peoria Subdivision (Nelson-Peoria/I&M Jct.)
Monterey Subdivision (I&M Jct.-Nilwood-Monterey Jct.-Madison IL)
Abandoned Lines
St. Charles Subdivision/Aurora Subdivision
Earlier Abandoned Lines
Lee County Cutoff (Nachusa-Nelson)
Alternate route on main line bypassed Dixon.
Fulton Line (Bluffs-Fulton-East Clinton)
Original route east of Clinton replaced with more direct Fulton Cutoff, now part of main line.
Kenosha Subdivision (Chicago-Kenosha)
Kenosha Subdivision (Kenosha-Milwaukee)
Milwaukee Subdivision (Proviso Yard-St. Francis)
Milwaukee Subdivision (St. Francis-Butler)
Harvard Subdivision (Chicago-Harvard)
Harvard Subdivision (Harvard-Janesville-Evanville)
Farm Subdivision (Kenosha-Bain-Rockford)
Beloit Branch (Clinton Jct.-Beloit)
Line Sold to CN (previously Fox River Valley Railroad and Wisconsin Central)
Air Line Subdivision (Milwaukee-West Bend/Eden-Fond Du Lac)
Abandoned Lines
Skokie Subdivision/Weber Subdivision
Adams Subdivision (Milwaukee-Wyeville)
Winona Subdivision (Wyeville-Tunnel City-Winona)
Waukesha Subdivision (Milwaukee-Waukesha-Cottage Grove)
Lines Sold to Wisconsin & Southern Railroad
Madison Subdivision (Evansville-Reedsburg-Elroy-Sparta)
Cottage Grove Subdivision (Cottage Grove-Madison)
Abandoned Lines
Beloit Subdivision/Footville Subdivision
Galesville Subdivision
Lancaster Subdivision/Platteville Subdivision
Clyman Subdivision (Janesville-Fort Atkinson-Clyman Jct.-Fond Du Lac)
Shoreline Subdivision (Milwaukee-Sheboygan)
Lines Sold to CN (previously Fox River Valley Railroad and Wisconsin Central)
Valley Subdivision (Fond Du Lac-Neenah-Green Bay)
Shoreline Subdivision (Sheboygan-Cleveland-Rockwood/Denmark-Green Bay)
New London Subdivision (Manitowoc-Kaukauna-New London-Antigo)
Line Sold to Wisconsin & Southern Railroad
Plymouth Subdivision (Kohler Jct.-Plymouth-Fond Du Lac)
Line Sold to Escanaba & Lake Superior Railroad
Oconto Falls Subdivision (Clintonville-Oconto Falls-Stiles Jct.-Oconto)
Abandoned Lines
Wisconsin Rapids Subdivision (Fond Du Lac-Marshfield)
Shawano Subdivision (Green Bay-Eland)
Laona Subdivision (Pulaski-Scott Lake)
Hortonville Subdivision/Nekoosa Subdivision
Red Granite Branch/Rosholt Branch/White Lake Branch
Wausau Subdivision (Eland-Marshfield)
Line Sold to CN (previously Fox River Valley Railroad and Wisconsin Central)
Marinette Subdivision (Green Bay-Escanaba)
Abandoned Lines
Rhinelander Subdivision (Antigo-Ashland)
Eagle River Subdivision (Monico-Watersmeet)
Wyeville Subdivision (Elroy-Camp Douglas-Altoona)
Altoona Subdivision (Altoona-Eau Claire-St. Paul)
Chippewa Falls Subdivision (Eau Claire-Chippewa Falls)
Line Sold to Wisconsin Northern Railroad
Spooner Subdivision (Chippewa Falls-Cameron-Spooner)
Line Sold to Wisconsin Great Northern Railroad
Hayward Subdivision (Spooner-Hayward-Bayfield)
Abandoned Lines
New Richmond Subdivision (Northline-Spooner)
Itasca Subdivision (Spooner-Superior)
Cornell Subdivision (Norma-Cornell)
Park Falls Subdivision/Merrillan Subdivision