Tom, I live in Flathead County, Montana, county seat of Kalispell.
This has always been a real gun builders mecca. Some of the builders in the area are Jerry Fisher, Monte Mandarino, Tim Mitchell, Lee Heglund, and John King, to name a few of the better known custom makers. Monte Kennedy used to live just south of me. I imagine there are at least two dozen active builders in this county easily, plus several top notch engravers, like Barry Lee Hands, and Larry Merical. Dan Goodwin and Franz Marktl also lived here.
Along with that, are several firearms manufacturers, barrel companies, and machine shops making gun parts. There is enough business of this type, that a reamer rental business moved here recently.
This is said to be the most heavily armed county in the United States.
Between Flathead, Saunders, Lincoln, and Lake counties here in the northwest corner of the state, I would say there is a definite school and style of building firearms.
I imagine the reason more isn't known about the builders in this area, many never really leave the area, or have private clientele that they build custom work for.