Still running into a dead-end looking for descendents of Carlos and Aimee Moser. So, I've been heading down two paths.
First, I'm trying to track down descendents of freighters from the areas, based upon this quote from http://brownvboard.org/brwnqurt/02-1/02-1d.htm.
"In the Boquillas area, the Gonzalez brothers of Saltillo, Coahuila, Mexico, and the Ben Gallego family of Alpine Texas dominated the industry."
There's a State Representative Pete Gallego from Alpine. Related?
Second, I've been researching the Glenn Springs Raid of 1916, a year after Moser's death. Mexican banditos (and maybe Villistas), attacked Glenn Springs, which is a few miles east of Boquillas. When they went back over the river, the histories talk about how they kidnapped the Doctor and Superintendent of the Puerto Rico mine.
The Americans where forced into their truck made to drive South. They pretended there were mechanical problems so they had to drive slowly. When most of the raiding party was a few miles ahead, kidnapped men stalled the engine and acted like it had died. They asked the remaining raiders to help push the truck and when they went to the back of the truck, the driver put it in reverse, knocking them down. The Americans grabbed banditos' guns and marched them back to the US, where they were handed over to the US Marshall.
If I can find the names of the people who worked in the mine, then I might be able to track down their descendents.
The Mosers remain ellusive...