A lot of coal mines had coal for sale pretty cheap. When I was a kid almost all campuses had coal fired boiler in the center of the campus, including schools and hospitals, even downtown businesses. You could buy coal at lumber yards, many houses had coal fired furnaces including ours.
I’m mostly familiar with mines in the west but there were many coal mines in the east. Arizona, New Mexico, Wyoming, Colorado, North Dakota and Montana have or had coal mines.
I guess in these days, I’d google “coal for sale” or ask at local lumber yards.
When I was attending the Univ of Idaho back in the '60's, there were steam tunnels connecting all the older buildings. They were off limits but many students would go down there and run around through them.
