The C&NW was my dad's favorite railroad when I was growing up, so I've got a few recommendations. First would be The 400 Story by Jim Scribbins. Second, would be any of the books by Patrick C. Dorin, who wrote several volumes on various aspects of the C&NW. The C&NW Final Freight Car Roster by Joe Pierson gives a very detailed history of all the car types, usually with photographic representation, when the C&NW was absorbed by UP. Finally, I would recommend any of the Morning Sun "In Color" series about the C&NW.
Thanks for the suggestions. I ordered the Grant C&NW book and will consult the C&NW historical society web page and the other sources.
In addition to selling back issues of the magazine "North Western Lines, the Chicago & North Western Historical Society's "Company store" sells some books that you might find interesting and worthwhile.
Two books on iron ore industry and mines in the context of the C&NW are published by the Society - this is pure "information" rather than text with photos but it might be helpful in documenting where relatives worked
For a more human interest type book, they sell "Life on a Locomotive" the story of one engineer, Buddy Williams, as told by his son but it names many names of colleagues and tells many stories. A somewhat similar book (with stories more than technical data about the C&NW) is "Life on the Shiny Iron" by Charles Bass. It is not available from the C&NWHS that I know of.
The C&NWHS published two excellent books with photos and information about facilities on the entire railroad -- turntables, roundhouses, coal tipples, that sort of thing - and of course Escanaba is in there but not solely Escanaba.
Patrick Dorin's old book on iron ore railroads is certainly worth seeking out.
The H Roger Grant history of the C&NW has much to say about Escanaba.
Although key scenes were filmed in Ishpeming rather than Escanaba, the wonderful movie "Anatomy of a Murder" gives a good flavor for C&NW railroading in that part of the Upper Peninsula of MI. And there are many other reasons to watch that film.
Dave Nelson
As always, when interested in a particular railroad, that railroad's historical society is a great place to start for information and leads. Besides the information they have themselves, they may be able to help you find members in that area that would have first-hand knowledge of what archives and records are available locally.
https://www.cnwhs.org/archives.htm
H. Rodger Grant wrote about the CNW that more than likely would fit your needs. He also wrote on the CGW and the Milwaukee Road.