This list of Colorado railroads identifies the variety of active, historic, and defunct railroads in the U.S. State of Colorado.__TOC__
| Name | Mark | System | From | To | Successor | Notes |
|---|---|---|---|---|---|---|
| Argentine Central Railway | 1905 | 1912 | Argentine and Gray's Peak Railway | |||
| Argentine and Gray's Peak Railway | 1913 | 1918 | N/A | |||
| Arkansas Valley Railroad | ATSF | 1900 | 1907 | Atchison, Topeka and Santa Fe Railway | ||
| Aspen Short Line Railway | 1888 | 1893 | Colorado Midland Railroad | |||
| Aspen and Western Railway | 1880 | 1892 | Crystal River Railway | |||
| Associated Railroads | none | AT&SF, CB&Q (BN), CRI&P, C&S (BN) and D&RGW | 1953 | 1988 | Regional Transportation District | Consortium formed to operate former Denver and Inter-Mountain Railroad line to the Denver Federal Center. Service provided alternately by C&S (BN) and D&RGW on behalf of the other owning railroads. |
| Atchison, Topeka and Santa Fe Railroad | ATSF | 1873 | 1895 | Atchison, Topeka and Santa Fe Railway | ||
| Atchison, Topeka and Santa Fe Railway | ATSF | ATSF | 1895 | 1996 | Burlington Northern and Santa Fe Railway | |
| Beaver, Penrose and Northern Railway | 1909 | 1920 | N/A | |||
| Book Cliff Railroad | 1899 | 1925 | N/A | |||
| Burlington and Colorado Railroad | CB&Q | 1881 | 1908 | Chicago, Burlington and Quincy Railroad | ||
| Burlington Northern Inc. | BN | 1970 | 1981 | Burlington Northern Railroad | ||
| Burlington Northern Railroad | BN | 1981 | 1996 | Burlington Northern and Santa Fe Railway | ||
| Busk Tunnel Railway | 1890 | 1900 | Colorado Midland Railway | |||
| Cadillac and Lake City Railway | CLK | 1981 | 1989 | N/A | ||
| Canon de Agua Railroad | CB&Q | 1889 | 1890 | Union Pacific, Denver and Gulf Railway | ||
| Canon City and Cripple Creek Railroad | 1897 | 1915 | N/A | |||
| Canon City and San Juan Railway | ATSF | 1877 | 1878 | Pueblo and Arkansas Valley Railroad | ||
| Canon Coal Railway | DRGW | 1872 | 1878 | Denver and Rio Grande Railway | ||
| Central Kansas Railway | CKRY | 1997 | 2001 | Kansas and Oklahoma Railroad | ||
| Chicago, Burlington and Quincy Railroad | CB&Q | CB&Q | 1881 | 1970 | Burlington Northern Inc. | |
| Chicago, Burlington and Quincy Railway | CB&Q | 1901 | 1907 | N/A | Leased the Chicago, Burlington and Quincy Railroad | |
| Chicago, Kansas and Nebraska Railway | RI | 1888 | 1891 | Chicago, Rock Island and Pacific Railway | ||
| Chicago, Rock Island and Colorado Railway | RI | 1888 | 1888 | Chicago, Kansas and Nebraska Railway | ||
| Chicago, Rock Island and Pacific Railroad | RI, ROCK | RI | 1947 | 1980 | Cadillac and Lake City Railway | |
| Chicago, Rock Island and Pacific Railway | RI | RI | 1888 | 1948 | Chicago, Rock Island and Pacific Railroad | |
| Chicosa Canon Railway | CB&Q | 1889 | 1890 | Union Pacific, Denver and Gulf Railway | ||
| Clear Creek and Guy Gulch Wagon Road Company | CB&Q | 1871 | 1873 | Colorado Central Railroad | ||
| Colorado Railroad | 1938 | 1957 | N/A | |||
| Colorado Railroad | CB&Q | 1906 | 1930 | Colorado and Southern Railway | ||
| Colorado Railway | DRGW | 1883 | 1888 | Denver and Rio Grande Railroad | ||
| Colorado Central Railroad | CB&Q | 1869 | 1890 | Union Pacific, Denver and Gulf Railway | ||
| Colorado Central and Pacific Railroad | CB&Q | 1866 | 1869 | Colorado Central Railroad | ||
| Colorado and Clear Creek Railroad | CB&Q | 1865 | 1866 | Colorado Central and Pacific Railroad | ||
| Colorado Eastern Railroad | 1894 | 1915 | N/A | |||
| Colorado Eastern Railway | 1888 | 1894 | Colorado Eastern Railroad | |||
| Colorado–Kansas Railway | 1911 | 1932 | Colorado Railroad | |||
| Colorado, Kansas and Pacific Railway | CKP | 2000 | 2003 | Towner Railway | ||
| Colorado Midland Railroad | CM | 1917 | 1921 | Midland Terminal Railway | ||
| Colorado Midland Railroad | 1893 | 1897 | Colorado Midland Railway | |||
| Colorado Midland Railway | 1897 | 1917 | Colorado Midland Railroad | |||
| Colorado Midland Railway | 1883 | 1893 | Colorado Midland Railroad | |||
| Colorado and New Mexico Railroad | ATSF | 1873 | 1875 | Pueblo and Arkansas Valley Railroad | ||
| Colorado Northern Railway | CB&Q | 1883 | 1884 | Denver, Utah and Pacific Railroad | ||
| Colorado and Northwestern Railroad | 1904 | 1909 | Denver, Boulder and Western Railroad | |||
| Colorado and Northwestern Railway | 1897 | 1904 | Colorado and Northwestern Railroad | |||
| Colorado and Pacific Wagon, Telegraph and Railroad Company | CB&Q | 1861 | 1871 | Clear Creek and Guy Gulch Wagon Road Company | ||
| Colorado and Salt Lake Railroad | CB&Q | 1871 | 1872 | Colorado Central Railroad | ||
| Colorado and Southeastern Railroad | C&SE | 1909 | 1952 | N/A | ||
| Colorado and Southeastern Railway | 1903 | 1909 | Colorado and Southeastern Railroad | |||
| Colorado and Southern Railway | C&S, CS | CB&Q | 1898 | 1981 | Burlington Northern Railroad | |
| Colorado Southwestern Railway | DRGW | 1888 | 1889 | Rio Grande Junction Railway | ||
| Colorado Springs and Cripple Creek District Railway | CCD | 1899 | 1920 | N/A | ||
| Colorado and Utah Railway | 1886 | 1892 | Crystal River Railway | |||
| Colorado and Wyoming Railroad | CB&Q | 1887 | 1908 | Chicago, Burlington and Quincy Railroad | ||
| Colorado, Wyoming and Eastern Railway | UP | 1914 | 1924 | Northern Colorado and Eastern Railroad | ||
| Colorado, Wyoming and Great Northern Railroad | 1894 | 1899 | Book Cliff Railroad | |||
| Cripple Creek and Colorado Springs Railroad | 1915 | 1921 | Midland Terminal Railway | |||
| Cripple Creek District Railway | 1897 | 1899 | Colorado Springs and Cripple Creek District Railway | |||
| Crystal River Railroad | 1898 | 1941 | N/A | |||
| Crystal River Railway | 1892 | 1898 | Crystal River Railroad | |||
| Crystal River and San Juan Railroad | 1906 | 1941 | N/A | |||
| Denver Railroad and Land Company | 1886 | 1887 | Denver Railroad, Land and Coal Company | |||
| Denver Railroad, Land and Coal Company | 1887 | 1888 | Colorado Eastern Railway | |||
| Denver Railway | DRWY | 1989 | 1993 | Denver Rock Island Railroad | ||
| Denver and Boulder Valley Railroad | UP | 1870 | 1898 | Union Pacific Railroad | ||
| Denver, Boulder and Western Railroad | 1909 | 1919 | N/A | |||
| Denver Circle Railroad | ATSF | 1880 | 1886 | Denver and Santa Fe Railway | ||
| Denver, Clear Creek and Western Railway | DRGW | 1888 | 1899 | Denver and Rio Grande Railroad | ||
| Denver, Cripple Creek and Southwestern Railroad | CB&Q | 1896 | 1899 | Colorado and Southern Railway | ||
| Denver, Golden and Salt Lake Railroad | CB&Q | 1881 | 1917 | Chicago, Burlington and Quincy Railroad | ||
| Denver and Inter-Mountain Railroad | D&IM, DIM | 1909 | 1953 | Associated Railroads (AT&SF, CB&Q, CRI&P, C&S and D&RGW) | Electric after 1909 | |
| Denver and Inter-Mountain Railway | 1904 | 1909 | Denver and Inter-Mountain Railroad | |||
| Denver, Lakewood and Golden Railroad | 1890 | 1904 | Denver and Inter-Mountain Railway | |||
| Denver, Laramie and Northern Railroad | 1917 | 1917 | Great Western Railway of Colorado | |||
| Denver, Laramie and Northwestern Railroad | 1910 | 1917 | Denver, Laramie and Northern Railroad | |||
| Denver, Laramie and Northwestern Railway | 1906 | 1910 | Denver, Laramie and Northwestern Railroad | |||
| Denver, Leadville and Gunnison Railway | CB&Q | 1889 | 1898 | Colorado and Southern Railway | ||
| Denver, Longmont and Northwestern Railroad | CB&Q | 1881 | 1883 | Colorado Northern Railway | ||
| Denver, Marshall and Boulder Railway | CB&Q | 1885 | 1890 | Union Pacific, Denver and Gulf Railway | ||
| Denver and Middle Park Railroad | CB&Q | 1883 | 1890 | Union Pacific, Denver and Gulf Railway | ||
| Denver and Montana Railroad | CB&Q | 1899 | 1908 | Chicago, Burlington and Quincy Railroad | ||
| Denver and New Orleans Railroad | CB&Q | 1881 | 1886 | Denver, Texas and Gulf Railroad | ||
| Denver, Northwestern and Pacific Railway | DRGW | 1902 | 1913 | Denver and Salt Lake Railroad | ||
| Denver Pacific Railway and Telegraph Company | UP | 1867 | 1880 | Union Pacific Railway | ||
| Denver and Rio Grande Railroad | DRGW | 1886 | 1921 | Denver and Rio Grande Western Railroad | ||
| Denver and Rio Grande Railway | DRGW | 1870 | 1886 | Denver and Rio Grande Railroad | ||
| Denver and Rio Grande Western Railroad | D&RG, D&RGW, DRGW | DRGW | 1920 | 1997 | Union Pacific Railroad | |
| Denver and Salt Lake Railroad | D&SL | DRGW | 1912 | 1927 | Denver and Salt Lake Railway | |
| Denver and Salt Lake Railway | D&SL | DRGW | 1926 | 1947 | Denver and Rio Grande Western Railroad | |
| Denver and Salt Lake Western Railroad | DRGW | 1924 | 1947 | Denver and Rio Grande Western Railroad | ||
| Denver and Santa Fe Railway | ATSF | 1887 | 1900 | Atchison, Topeka and Santa Fe Railway | ||
| Denver, South Park and Hill Top Railway | CB&Q | 1896 | 1897 | Denver, Leadville and Gunnison Railway | ||
| Denver, South Park and Pacific Railroad | CB&Q | 1873 | 1889 | Denver, Leadville and Gunnison Railway | ||
| Denver, South Park and Pacific Railway | CB&Q | 1872 | 1873 | Denver, South Park and Pacific Railroad | ||
| Denver and Southwestern Railway | 1899 | 1904 | Cripple Creek Central Railway (holding company) | |||
| Denver Terminal Railroad | DTMR | 1986 | 1989 | Denver Railway | ||
| Denver, Texas and Gulf Railroad | CB&Q | 1885 | 1890 | Union Pacific, Denver and Gulf Railway | ||
| Denver, Texas and Fort Worth Railroad | CB&Q | 1887 | 1890 | Union Pacific, Denver and Gulf Railway | ||
| Denver Union Railway and Terminal Company | UP | 1889 | 1900 | Union Pacific Railroad | ||
| Denver Union Terminal Railway | DUT | ATSF/ CB&Q/ DRGW/ RI/ UP | 1912 | 2001 | Regional Transportation District | |
| Denver, Utah and Pacific Railroad | CB&Q | 1880 | 1908 | Chicago, Burlington and Quincy Railroad | ||
| Denver, Western and Pacific Railway | CB&Q | 1880 | 1885 | Denver, Marshall and Boulder Railway | ||
| Elk Mountain Railway | 1887 | 1898 | Crystal River Railroad | |||
| Florence and Cripple Creek Railroad | 1893 | 1915 | Cripple Creek and Colorado Springs Railroad | |||
| Fort Collins Development Railway | CB&Q | 1902 | 1908 | Colorado Railroad | ||
| Fort Worth and Denver Railway | FWD | CB&Q | 1881 | 1982 | Burlington Northern Railroad | |
| Georgetown, Breckenridge and Leadville Railway | CB&Q | 1881 | 1890 | Union Pacific, Denver and Gulf Railway | ||
| Gilpin Railroad | CB&Q | 1909 | 1917 | N/A | ||
| Gilpin Tramway Company | CB&Q | 1886 | 1906 | Gilpin Railroad | ||
| Golden Circle Railroad | 1896 | 1915 | Cripple Creek and Colorado Springs Railroad | |||
| Golden City and Gilpin County Wagon and Railroad Company | CB&Q | 1870 | 1872 | Colorado Central Railroad | ||
| Golden City and South Platte Railway and Telegraph Company | 1872 | 1880 | N/A | |||
| Grand Valley Railway | DRGW | 1886 | 1887 | Denver and Rio Grande Railroad | ||
| Greeley, Salt Lake and Pacific Railway | CB&Q | 1881 | 1890 | Union Pacific, Denver and Gulf Railway | ||
| Greeley Terminal Railway | 1909 | 1917 | N/A | |||
| Holly and Swink Railway | ATSF | 1906 | 1907 | Atchison, Topeka and Santa Fe Railway | ||
| Kansas–Colorado Railroad | 1908 | 1910 | Colorado–Kansas Railway | |||
| Kansas Pacific Railway | UP | 1869 | 1880 | Union Pacific Railway | ||
| Laramie, Hahns Peak and Pacific Railway | UP | 1911 | 1914 | Colorado, Wyoming and Eastern Railway | ||
| Laramie, North Park and Western Railroad | UP | 1924 | 1951 | Union Pacific Railroad | ||
| Larimer and Routt County Railway | UP | 1907 | 1914 | Colorado, Wyoming and Eastern Railway | ||
| Leadville Mineral Belt Railway | CB&Q | 1898 | 1900 | Colorado and Southern Railway | ||
| Leadville, Ten Mile and Breckenridge Railway | DRGW | 1880 | 1880 | Denver and Rio Grande Railway | ||
| Little Book Cliff Railway | 1889 | 1894 | Colorado, Wyoming and Great Northern Railroad | |||
| London, South Park and Leadville Railroad | 1882 | 1885 | South Park and Leadville Short Line Railroad | |||
| Longmont and Erie Railroad | CB&Q | 1878 | 1881 | Denver, Longmont and Northwestern Railroad | ||
| Midland Terminal Railway | MTR | 1892 | 1949 | N/A | ||
| Missouri Pacific Railroad | MP | MP | 1917 | 1997 | Union Pacific Railroad | |
| Missouri Pacific Railway | MP | 1887 | 1917 | Missouri Pacific Railroad | ||
| Mount Carbon, Gunnison and Lake City Railroad and Coal Transportation Company | CB&Q | 1877 | 1881 | Denver, South Park and Pacific Railroad | ||
| Nebraska, Kansas and Colorado RailNet | NKCR | 1996 | 2005 | Nebraska Kansas Colorado Railway | ||
| Northern Colorado and Eastern Railroad | UP | 1924 | 1924 | Laramie, North Park and Western Railroad | ||
| Northwestern Terminal Railroad | DRGW | 1927 | 1968 | Denver and Rio Grande Western Railroad | ||
| Northwestern Terminal Railway | DRGW | 1904 | 1927 | Northwestern Terminal Railroad | ||
| Platt Valley Railway | 1993 | 1993 | Denver Rock Island Railroad | |||
| Pueblo and Arkansas Valley Railroad | ATSF | 1875 | 1900 | Atchison, Topeka and Santa Fe Railway | ||
| Pueblo and Salt Lake Railway | ATSF | 1873 | 1875 | Pueblo and Arkansas Valley Railroad | ||
| Pueblo and State Line Railroad | MP | 1887 | 1910 | Missouri Pacific Railway | ||
| Pueblo Union Depot and Railroad Company | ATSF/ CB&Q/ DRGW/ MP/ RI | 1887 | ||||
| Rio Grande Railroad | DRGW | 1900 | 1908 | Denver and Rio Grande Railroad | ||
| Rio Grande Gunnison Railway | DRGW | 1891 | 1908 | Denver and Rio Grande Railroad | ||
| Rio Grande Junction Railway | DRGW | 1889 | 1947 | Denver and Rio Grande Western Railroad | ||
| Rio Grande, Pagosa and Northern Railroad | DRGW | 1899 | 1908 | Denver and Rio Grande Railroad | ||
| Rio Grande and Pagosa Springs Railroad | 1895 | 1914 | N/A | |||
| Rio Grande, Pueblo and Southern Railroad | DRGW | 1902 | 1908 | Denver and Rio Grande Railroad | ||
| Rio Grande Sangre de Cristo Railroad | DRGW | 1901 | 1908 | Denver and Rio Grande Railroad | ||
| Rio Grande Southern Railroad | DRGW | 1889 | 1951 | N/A | ||
| Rio Grande Western Railway | DRGW | 1889 | 1908 | Denver and Rio Grande Railroad | ||
| Road Canon Railroad | CB&Q | 1889 | 1890 | Union Pacific, Denver and Gulf Railway | ||
| St. Joseph and Iowa Railroad | RI | 1888 | 1888 | Chicago, Rock Island and Pacific Railway | ||
| San Luis Southern Railway | 1909 | 1928 | San Luis Valley Southern Railway | |||
| San Luis Valley Southern Railway | 1928 | 1953 | Southern San Luis Valley Railroad | |||
| Silverton Railroad | 1887 | 1904 | Silverton Railway | |||
| Silverton Railway | 1904 | 1922 | N/A | |||
| Silverton, Gladstone and Northerly Railroad | 1899 | 1915 | Silverton Northern Railroad | |||
| Silverton Northern Railroad | 1895 | 1941 | N/A | |||
| South Park and Leadville Short Line Railroad | 1885 | 1900 | N/A | |||
| Southern San Luis Valley Railroad | SSLV | 1953 | 1996 | N/A | ||
| State Line and Denver Railway | DRGW | 1889 | 1889 | Rio Grande Western Railway | ||
| Trinidad Railway | TRIN | 1992 | Still exists as a joint lessor of the BNSF Railway and Union Pacific Railroad | |||
| Trinidad and Denver Railroad | DRGW | 1886 | 1888 | Denver and Rio Grande Railroad | ||
| Trinidad and Denver Terminal and Railway Company | DRGW | 1888 | 1899 | Denver and Rio Grande Railroad | ||
| Uintah Railway | 1903 | 1939 | N/A | |||
| Union Depot and Railroad Company | ATSF/ CB&Q/ DRGW/ RI/ UP | 1879 | 1899 | Union Depot and Railway Company | ||
| Union Depot and Railway Company | ATSF/ CB&Q/ DRGW/ RI/ UP | 1899 | 1914 | Denver Union Terminal Railway | ||
| Union Pacific Railway | UP | 1880 | 1898 | Union Pacific Railroad | ||
| Union Pacific Railway, Eastern Division | UP | 1866 | 1869 | Kansas Pacific Railway | ||
| Union Pacific, Denver and Gulf Railway | CB&Q | 1890 | 1898 | Colorado and Southern Railway | ||
| Union Pacific, Lincoln and Colorado Railway | UP | 1888 | 1898 | N/A | Sold at foreclosure; no property in Colorado | |
| Walsenburg and Western Railway | CB&Q | 1907 | 1910 | Colorado Railroad |