https://countrysportscotland.com/deer-stalkinghunting/

Looking at their web page, I see where you came up with your choice of game animals.

That terrain looks more like western USA to me than east of the Mississippi, just from a quick 2 minute glance through their web page. There isn't going to be a list of game animals like that wandering the western USA in the next 100 years even if humans were wiped off the planet today.

Write what you know or at least as close to it as you can. I'd set that location in Northern Scotland if I were you. The same weapons we have been discussing are probably pretty common there thanks to the WWII lend lease program between out countries. I'd read that book regardless of either location just the same.