surface mining of hard coal (Pennsylvania)

Our very droll friend T found this postcard in a vintage shop and immediately thought of us, sending it along posthaste! They’re so funny that I just have to quote directly: “Nothing says ‘Wish you were here’ quite like an open pit mine & slag heap. Found this card in a junk shop, no idea when it’s from but I would guess 70s-80s? These were the fertile playgrounds of my youth and hope you can visit them someday. America runs on coal!” I couldn’t have said it better myself!