That’s a big hole! We have an iron ore quarry that worked in the southern California desert from before WWII until the 80s, And trains would take the order back near Los Angeles to smelt it. Those years that the Kaiser steel mill was operating were terrible on our lungs when I was growing up. Have you flown near where they did the smelting for the copper? It would be interesting to see what the environment looks like around it, copper smelters usually put out a lot of really bad pollution, Including arsenic, lead and other metals, and sulfides that contaminate the soil and kills nearby trees.. Nice imagery. You really have a lot of beautiful forests and mountains near that copper quarry!