Antonito Branch Facts
From: Alamosa, CO
To: Antonito, CO
Miles: 28.6
Built: 1879 (NG)
To 3R: 1901
To SG: 1970
What's considered the Antonito Branch here was arguably just the humble beginnings of the Santa Fe Branch. The Rio Grande's original reason for building into the San Luis Valley was to reach the headwaters of the Rio Grande (river) and then follow the water-grade route all the way down to Albuquerque and El Paso. In 1879, keeping with this original goal, the first 29 miles from Alamosa to Antonito were graded, with rail being put down early in 1880. While for the sake of categorization I keep them separate as the Antonito Branch, they were really built as the first leg in the stretch towards Albuquerque. Only later did it become an important connector not only with the Santa Fe Branch, but also with the much more important San Juan Extension, which branched off at Antonito. Eventually, it would be considered part of the narrow gauge main westward, part of Subdivision 11 (the San Juan Extension).
With the opening of the new La Veta Pass line in 1899, there was interest in spreading standard gauge as far as it could practially go throughout the valley. With important agricultural commodities flowing out of the Alamosa-Antonito segment, a third rail was added to the segment in 1901 to allow them to be directly loaded into standard gauge cars for shipment to Denver. However, since the route was still a vital connector in the narrow gauge network, dual gauge was maintained. With the engine shops and major yard being in Alamosa, the dual gauge lasted longer here than anywhere else on the Grande system. It wasn't until the narrow guage San Juan Extension was fully abandoned west of Antonito in 1970 that the line was converted to purely standard gauge.
The Antonito Branch remained to the very end of the Rio Grande. It passed to the Southern Pacific Railroad in 1989, followed by the sale of the SP to Union Pacific in 1996. UP, in turn, spun off the San Luis Valley lines in 2003 to a new RailAmerica shortline - the San Luis & Rio Grande Railroad. The SLRG ran for a few years, and in December of 2005, the route was sold from RailAmerica to Iowa Pacific Holdings, who continues to operate it under the same name. For more information, see the "Current Operators" page on the SL&RG.
Antonito Branch Timetable
