What sort of mine are you looking to build? There is quite a bit of difference in the type of structures one might find in a turn-of-the-century shaft coal mine in the East/Mid West compared to prospector type mines found at the same time out west.
If you can find some of the back issues of Model Railroader, Railroad Model Craftsman, and some of the defunt MR publications like Motel Trains and Railroad Modeler, There is a chance of finding quite a variety of facilities ranging from simple ramps for a dump tuck to back up and dump into a waiting hopper to several mine buildings large enough to require being serviced by one or two switchers with a need for a mall yard to provide hoppers for several loading track.
In fact, I’d almost suspect the Backman or similar coaling tower could be kitbashed with an angled housing into a hillside and a couple outbuildings to serve.
I don’t believe dehusman explained. This is on the Library of Congress website. www.lov.gov.
In that site, go to “American Memory” and then to, I believe it is either Engineering or Buildings. They probably have plans and photos for tens of thousands of history buildings and structures.
Some plans and articles about mines in model railroad publications:
COAL MINE Coal loader, Ajax Loader #2 HO constrn article RMC Oct94 p.59 Coal mining- explosive mining pre-1965 w varied coal sizing vs continuous mining machine producing uniform sizes, conveyors, eqpt, elevator tower N Scale MayJun2000 p.50 Morley Mine, Morley Colorado on Plans, N & HO models
Here is a link to Virginia Tech’s “Imagebase” which houses approx 10,000 of N&W’s official photographer’s photos. This particular link is to a section labeled “Coal Companies, Mines, and Tipples”