Denver and Rio Grande Western Railroad
The Denver and Rio Grande Western Railroad (reporting mark DRGW), often shortened to Rio Grande, D&RG or D&RGW, formerly the Denver & Rio Grande Railroad, was an American Class I railroad company. The railroad started as a 3 ft (914 mm) narrow-gauge line running south from Denver, Colorado, in 1870.
Source: Wikipedia — Denver and Rio Grande Western Railroad (CC BY-SA 4.0)