| ABD | Allouez Bay Dock Co. | 1903- | | GN |
| B&NM | Brainerd & Northern Minnesota | 1892-1901 | Gull Lake Lumber | M&I, NP |
| BB&E | | 1892-1903 | | NP |
| BCR&N | Burlington, Cedar Rapids & Northern | 1876-1902 | Burlington, Cedar Rapids & Minnesota | CRI&P |
| BDL&S | Brandon, Devils Lake & Southern | 1905- | | GN |
| BF&IF | Big Fork & International Falls | 1906-1923 | | NP |
| BF&N | Big Fork & Northern | 1905 | | M&I, NP |
| BN | Burlington Northern | 1970- | NP, GN, CB&Q, SP&S, WV | BNSF |
| BNSF | Burlington Northern-Santa Fe | 1995- | Burlington Northern: Santa Fe | |
| BW | Bayfield Western | 1901-1903 | | NP |
| C&GW | Chicago & Great Western | 1885-1890 | | C&NP |
| C&M | Caledonia & Mississippi | 1873- | | CM&StP |
| C&NP | Chicago & Northern Pacific | 1890-1897 | Chicago & Great Western | WC (NP), CTT |
| C&NW | Chicago & North Western | 1864- | Chicago, St. Paul & Fond du Lac | C&NW |
| C&PS | Columbia & Puget Sound | 1880-1916 | Seattle & Walla Walla; Seattle Coal & Transport | PCC |
| C&RM | Columbia & Red Mountain | 1895-1907 | | GN |
| CB | Casselton Branch | 1880- | | NP, GN |
| CB&N | Chicago, Burlington & Northern | 1885-1899 | | CB&Q |
| CB&Q | Chicago, Burlington & Quincy | 1856-1970 | Chicago & Aurora | BN |
| CCD&M | Chicago, Clinton, Dubuque & Minnesota | 1878-1880 | Clinton & Dubuque; Dubuque & Minnesota | CM&StP |
| CD&M | Chicago, Dubuque & Minnesota | 1871-1877 | Dubuque & Minnesota | D&M, CCD&M, CM&StP |
| CdAR&N | Coeur d'Alene Railway & Navigation | 1886-1888 | | NP |
| CE | Centralia Eastern | 1909-1917 | | NP |
| CGW | Chicago Great Western | 1893-1968 | Chicago, St. Paul & Kansas City | C&NW |
| CIR | Cuyuna Iron Range | 1908- | | Soo |
| CM&PS | Chicago, Milwaukee & Puget Sound | 1909-1912 | | CM&StP |
| CM&StP | Chicago, Milwaukee & St. Paul | 1874-1927 | Milwaukee & St. Paul | CMStP&P |
| CM&W | Caledonia, Mississippi & Western | 1879-1880 | | CCD&M, CM&StP |
| CMStP&P | Chicago, Milwaukee, St. Paul & Pacific | 1926- | | CMStP&P |
| CN | Canadian National | | | |