Those first miners who found them called them Cavernites, because they had no other name for the pale people. They were deep underground in the Mule Mountains, under territory that hadn't even been named, much less explored.
The Qinti, as they call themselves, had been driven northward by fear and the promise of their Spirits until there, beyond the sight of their warlike neighbors, the ravaging conquistadors and encroaching pioneers, they found a place that thought could not be conquered. They built their haven in the natural caverns of the mountains, using the very stones which surrounded them and reveling in the beauty of the Earth. They did not seal the opening through which they found the caverns, but they camouflaged it well, and used it to take their livestock to pasture and work the terraces they built into the sides of the mountain. They called that opening the Last Gate, and they called the bowl-shaped meadow they farmed the Blessed Shakra. Their Chaskis, the spirit-workers, built a strong defensive shield around their new homes so that strangers would not wander too close, and even the curiosity of prying eyes would be quenched. They did their work well, tying the strength of the shield to the strength of the mountain they believed to be eternal, unshakable. For many generations, the Qinti lived in seclusion, safe in their mountain home. When the newly-minted United States government bought the Arizona territory, nobody thought anything of that blank spot on the map, just a few hundred acres in the middle of the Mule Mountains. When the dynamite and the big machines of the mining operations began, the Chaskis felt the tremble, and began to worry - something unnatural was happening to the mountain range, but they didn't know what. They felt the disruption, but couldn't identify it. They never dreamed a threat would come from within the Earth. They didn't think that was possible.
The miners didn't know all that. They weren't even sure those Cavernites had a spoken language, or could speak at all. The Company figured those people must just be stubborn, of course they could talk, but did it really matter? The people who had carved out those glorious caverns were surely talented miners, and those cities would be worth a fortune, once dismantled and parceled into salable chunks. Probably should keep this hushed though, wouldn't want the competition to get wind of this. If those people did turn out to be mute, so much the better.
Sensing an opportunity, the miner's union offered to keep the secret in exchange for better pay and shorter shifts. In the Company's eyes, those miners were suddenly expendable, and dangerous. More time off would give them more time in town, more chances to spread the news. That just wouldn't do. As the miners's union called for a strike, the Company was making arrangements for new workers to be shipped in on trains. They wouldn't need so many, now. A few dozen workers who didn't strike with the union were held at the company operations center, for their own safety, the managers said. They were promoted, and tasked with building barracks adjacent to the operations center. In the meantime, the managers told them to sleep there in tents procured by the Company - the townsfolk would kill them, the managers said; the striking miners would be so angry. The barracks went up with a quickness. The newly-promoted miners were issued shiny starched uniforms and encouraged to think of themselves as the lawmen of the mine, answerable only to the managers. They started calling each other "Officer -" and "Sir."
Outside the mine, a massacre was being committed, one miner at a time, from the old oak tree on Sacramento Hill. The swinging bodies were disposed of in an old dry shaft, which collapsed under a sudden cave-in just as the last bodies were dumped, trapping the executioner and his aids in their shiny new uniforms. Oh, such a loss, said the managers when the security guards didn't return from their special, secret, mission. Well, back to work boys, back to work. We'll honor their memory by moving on. These mines won't work themselves.
The new workers were processed right from the rail cars. They never even knew there was a town outside the company's fence. Out in the middle of the desert, they thought, not a soul in sight but the managers and the security guards.
