A very enjoyable pair of articles, and it was great to read about the "local color" as opposed to concentrating purely on the vans.
Having used the Milepost for several trips in Alaska, NWT and the Yukon (mostly by bicycle) I'd say that not every establishment along the roads is listed in the Milepost, and there appears to be some correlation between being listed and having advertising in the guide. Thus, you will come across more services than the guide would suggest.