CEMEX Has some new rail-served distribution centers in California Colorado. They operate a railway but I'm not sure how far it goes with material. They do have have lots of quiet places where trucks and trains aren't out of place .
Take a look at the map in the center of the link, search any rail operator you like for details.
Trying to find one more source map for researchers. Train tracks missing kids are practically synonymous
http://www.railpictures.net/index.php
I know we are missing 21 trillon from the DOD and HUD so if we funded a breakaway civilization, CEMEX built it. I suppose it adds some extra credence to the DUMS rumors.
You might poke around Victorville in case anybody is feeling inclined. It's not too far from Palmdale and Palmdale is run solidly by MS-13. The Santa Clara The Valley Signal newspaper may have some interesting stories in their morgue, small papers do a much better job at the work.
I'd look at old Portland Cement facilities too.
This is solid as hell. You got em, now you need to work your way around the gatekeepers. Any kid that hops rails and moves with homeless encampments will know where I bet.
Seems like everyone knew this but us.
https://youtu.be/1bA9UNPqKv8