Any idea when the Blue Mountain Quarry was first founded?

First off, I know the CGI era doesn't really do "dates" or much for timeline, and the time scale is pretty sketchy at best, so if there's not really an answer to this then oh well, moving swiftly on.

But also, I figured I'd ask the masses if there's any sort of consensus, popular head canons, information to go off of, or what now 😅