That's all Oklahoma, not Colorado. It's in Devils canyon, at the west end of the Wichitas. It's not really Soldier Mt., but there is a Soldier Springs east of the site. The Spanish allegedly had a road that ran near here along the north fork of the Red River. There was a large Wichita village there, and possibly some Spanish occupation. Lot of history there, too much to list. The soldiers fought some Comanches there in 1868 near Soldier Spring. Supposedly, some Kiowas took some gold from the Spanish and went east to Twin Mts. and buried it. Maybe. I been all over Twin Mts. but didn't find much, but it is an interesting area. Lots of rattlers, too. My great uncle worked the area around Devil's Canyon looking for something, back in the old days when you could pretty much go anywhere, but never found what he was looking for. If you can find transcripts of the Greer County case, there's a bonanza of historical info there about that area. And keep in mind, just because you find Spanish artifacts in SW Oklahoma doesn't mean the Spanish was there. Often overlooked, but the Kiowas and Comanches were all the time trading with and going down raiding in Mexico, where they confiscated property belonging to the Spanish. So the random Spanish bridle bit found in SW OK could very well have belonged to a Comanche warrior.