For RGS lumber info, RGS Story Vols 6 (Rust Lumber Co) and Vol 7 (McPhee / Montezuma Lumber) both have lots of info. There's sawmill info in Vol 8
as well.
Silver San Juan also has a suprising amount of info on lumber operations on the RGS. Although an old book, you can still find copies pretty easily.
My books page has links to find many of these books, and many of them you can purchase online. Those same sources are probably good places to look for EBT books.
(and as always, if you know of more/better places, let me know and I'll add those too!).