Thanks for the info!
Yes, that's the area that I was referring to, but looking at it again, I think it's not the correct size. It's smaller than what I initially thought it was based on my estimate of the box sizes on this map (I was wrong, I think):
https://data-ndom.opendata.arcgis.com/pages/mining-claims
Presumably the entire area they have access to between the two mountain ranges is ~8000 acres.