Hopefully someone will chime in with a good coal source for you but if you can't find coal near you consider using charcoal. I don't know if it's the same in Alabama but here is SC we can buy lump charcoal in places like Wal-Mart & Lowes...just make sure it's real charcoal and not the briquettes. You can also make your own charcoal. A lot of folks also use dried corn as fuel. I don't have any personal experience with corn I understand that it works great. Best of luck to you!
By the way, walking the RR tracks is considered trespassing so I can't condone that BUT I used to do the same thing and had great luck! Amazing how much coal spills from the cars.