Are you coming near the east part of the state plenty of coal mines here:D
Just stop in the main office adn see if they will take you around , I dont know about going in a underground mine being a vistor, But a surface mine should be no problem, but stop in office first there very dangeous in winter time mud foot thick on roads and heavy equipment pulling trucks up moutians etc. I used to work mines found a petrifed wood piece big as your leg and lots of fossils
If yuo go to Fort Boonesborough more of the middle of the state , there is a big mine right there on the river salt i think they drive big trucks in um different than coal mines, but you can drive back in them for miles it seemes