Wildman1, I am a member of the NMLRA, and, in fact, will be set up there in Booth A66 at the Fall Shoot in September as a vendor!
Forty Rod, the name I picked is a catch-all, meant to cover everything West of Independence, Missouri! I include the Rockies and the Great Basin, and even California itself in my vision! Don't let the name fool ya, pard! A lot of those old Mountain Men became "plainsmen" of sorts after the fur trade played out, and they became scouts and such for the Army and wagon trains heading west, as you well know,as an historian yourself.
Oregon, I'm glad you like the idea! I need to "flesh it out" and see what we can make of it.
As for it not being able to cover the era properly because of its diversity, the NMLRA folks and the AMM folks do a pretty good job of covering everything from the French & Indian War (and before) through 1840! And that covers a LOT of ground and equipment changes & developments!
Who knows? We might have something here! I'm sitting in Iraq right now, but will be home in June. Hopefully, more pards will climb on board with this as well!
Regards,
Jake