West Gunnison Main Facts
Note: Perhaps no part of the Rio Grande system has undergone such changes in its purpose or operations as the section between Montrose and Grand Junction. To make it understandable no matter what portion of history you're in, I've referred to it as the "West Gunnison Main". However, the Rio Grande would have considered Montrose-Grand Junction to be the western part of the Third/Gunnison Division mainline until the standard-gauging in 1906, and then later the Grand Junction-Delta section would be considered part of the North Fork Branch, while the Delta-Montrose segment would become part of the Ouray Branch.
After building west via Marshall Pass and the Black Canyon, the original narrow gauge mainline of the Denver & Rio Grande turned northwest from Montrose, CO?, to follow the Uncompahgre and Gunnison Rivers into Grand Junction, CO. As with the line from Gunnison, these 74 miles were completed in 1882.
The line had one of only two tunnels on the narrow gauge mainline to Salt Lake City. Originally, the railroad crossed the Gunnison River four times in a very short stretch near Bridgeport, CO?. In September 1883, only five months after the first through train to Salt Lake passed over the line, the D&RG contracted to have a half-mile tunnel built to bypass those bridges. By 1884, narrow gauge trains were moving through the 2252-ft Bridgeport Tunnel instead.
In 1887, Montrose became not just an important point on the narrow gauge mainline, but also the junction with the Ouray Branch. Another narrow gauge branch was added off the line in 1902, when track was run east from Delta, CO?, towards Somerset to create the North Fork Branch.
Due to climbing agricultural and coal traffic from west of the Black Canyon and bound for standard gauge destinations - coupled with the dwindling importance of the narrow gauge mainline via Marshall Pass - the decision was made to standard gauge the Grand Junction to Montrose line in 1906. At the same time, the North Fork Branch was also upgraded.
The next major change came in 1953, with the abandonment of the last few miles of the Black Canyon line east from Montrose to Cedar Creek and the standard gauge of the Montrose-Ridgway remnant of the Ouray Branch. At that point, from an operational standpoint the North Fork? encompassed the track from Grand Junction, CO, through Delta all the way to the mines at Somerset, CO?, and Paonia, CO?. The section of the old main between Delta, CO?, and Montrose, CO? operationally became the north end of the Ouray Branch.
Today, the Grand Junction-Delta segment continues to be a vital part of Union Pacific Railroad?'s North Fork Branch coal operations, handling 3-4 loaded coal trains and an equal number of empties every day. The Delta-Montrose segment is now known as the Montrose Industrial Lead, and is served by a weekly local out of Grand Junction.