Actually you couldn't go wrong by perusing the November 1977 issue of the NG&SL Gazette Red Mountain on the Wye article. Although about the Silverton Railroad the techniques used there with sifted raw white plaster to partially cover the ground and structure rooves are very realistic. The module took Best in Show at Valley Forge NMRA convention.
If you can't locate a copy I could shoot the pages.
What do you mean by Alpine station?The Stone Enginehouse and Bunkhouse? TheTelegraph office?Joe Crea had plans and a construction article for the Telegraph office.Joe had Enginehouse plans-Its small enough in HO that you can fit the whole thing in your layout .Alpine station is clear over on the other side of St.Elmo-also known as Fisher.Don't forget the snow sheds-there's one photo taken from the top of the pass that shows the Enginehouse and sheds completely buried.Why do you think they shut down in winter ?