That American Borate car sent me into the internet cellar.
American Borate actually does its mining in Turkey, but it's a large supplier to Owens Corning among others. Product is imported then distributed by truck and rail. [
www.americanborate.com]
American PACIFIC Borate (not American Borate) has an active mine near "Fort Cady" California, which is in the middle of nowhere, south of Hector on the BNSF Needles Sub, and near the north border of the 29 Palms Marine training area. [
www.google.com] They have an interesting access road looking at Google Maps - dirt, but large and heavy duty, and aligned almost like a railroad spur. The company's materials appear to say that they have a railroad spur, but I don't see any more than the usual setout track at Hector - didn't do a more exhaustive search of the area.
The largest borax mine in the US, and one of the largest in the world, is also in California on BNSF: the
Rio Tinto operation at Boron. [
www.google.com] That one definitely does have railroad activity, quite a lot of it. Cars from there might be operating under the US Borax name - the company that developed the mine and was absorbed by the Rio Tinto conglomerate. Kramer/Boron makes the Fort Cady operation look tiny.
In addition to the famous colemanite borax mines around Death Valley (served at one time by the Tonopah & Tidewater), borates have been produced at Trona (Trona RR). Then there are all the other small operations around the western US at one time or another.
I climbed out of the basement before diving in even deeper. The history of borax/borate mining has probably been the foundation of many careers and obsessions. Beware if you're thinking of jumping in there without personal mental protection!
Trona and Boron in the same shot!