Los Almagres was an area in today’s Llano County that was prospected, and almost certainly mined, during the Spanish colonial era. It is often confused with the San Saba presidio as they were in operation in more or less the same time frames.
There are Spanish era shafts in Llano County, but no one has reported finding slag around them. Slag would be evidence of smelting with flux and charcoal in a blast furnace type arrangement.
Los Alamagres had a problem with Indians killing miners, but certain seasons of the year the Indians were not there. Could miners have dug up ore at Los Almagres during the safe season, then transported it some safer place to refine it during the seasons the Indians passed through Los Almagres?
What would be a safe place not too far away? Something like a stone fortress–how about the San Saba fort the Spaniards abandoned in 1772? The San Saba Presidio area had water, and timber for charcoal — all essentials for smelting.
This hypothesis explains the following:
- Why the remains of a smelter and slag was found at the San Saba Presidio by Anglos later on. A sample of the slag tested positive for silver.
- Why no slag was found in Llano county.
- Legends about mines on the San Saba — refining can be as big a job as mining, and perhaps the miners really spent most of their time there, so it entered the folklore in San Antonio.
Why not tell the Spaniards that there was silver at Los Almagres and gain military protection? That had already been tried and protection was refused–probably due to politics as to who would be the Presidio commander. Why refine it at the abandoned fort instead of in San Antonio? Doing it nine days to the north of San Antonio would have kept it secret from the Spanish authorities and evaded the 20% tax.
Not much evidence for this theory, but it certainly explains a lot.