Antonito was the end of Rio Grande dual gauge tracks. South of Antonito was narrow gauge territory. Rio Grande shipped a lot of different cargos to and from the area served by the narrow gauge system. The transfers from narrow gauge cars to standard gauge cars were made in Alamosa.
Antonito was the southern end of the standard gauge tracks in the valley. The old the depot was abandoned when I visited Antonito in the end of the 90s. Antonito is also the eastern end of Cumbres & Toltec Scenic Railroad. The company uses the old narrow gauge line from Antonito to Chama for tourist traffic. C&TSRR have some facilities in the southern part of the city.
The main products that was shipped from Antonito by rail was Perlite, Scoria and decorative rocks. The Perlite business was dominating the traffic. The Perlite plant is south of Antonito along the old Chili Line. The ghost railroad can easily be traced south from the end of the Perlite yard. The perlite business is important for San Luis & Rio Grande Railroad, who runs the rail road in the valley today.
The Perlite comes from No Agua, New Mexico - about 20 miles south. The scoria comes from Red Mountain, New Mexico - about 4 miles from No Agua. That's close to Volcano for you Chili Line fans. Everything is trucked to Antonito. Cars are set out at the loading facilities and the coming and going of cars is active. Only one locomotive goes down into the yard and plucks out cars and takes them a short way up the mainline where the train is made up. The Antonito yard is separated from the Cumbres & Toltec yard by only 100 feet or so and Perlite cars are often to be seen parallel to the C&TSRR station track. The standard gauge tracks and narrow gauge tracks are not connected.
Perlite is not a trade name but a generic term for naturally occurring siliceous rock. The distinguishing feature that sets Perlite apart from other volcanic glasses is that when heated to a suitable point in its softening range, it expands from four to twenty times its original volume.
It is widely used as a loose-fill insulation in masonry construction. Other construction applications include under-floor insulation, chimney linings, paint texturing, gypsum boards, ceiling tiles and roof insulation boards.
Industrial applications for Perlite are the most diverse, ranging from high performance fillers for plastics to cement for petroleum, water and geothermal wells. Other applications include its use as a filter media for pharmaceuticals, food products, chemicals and water for municipal systems and swimming pools.