If you're coming across from WA on US 2, pretty much everything to the East of Glacier is infested with some form or another of varmint. Prairie dogs, moles, rabbits, and even coyote and the occasional skunk, porcupine, etc. all across the "high plains" region. I just recommend you wait until you pass through the reservation before asking.
It's all farm and ranch country, and they have no love for the little pests.
One thing you will encounter on occasion is the "ya ain't from 'round here" mentality. Even I get it despite being Montana born and raised and living in the "hi-line" area for a decade. Because I'm from a different part of the State, I'm still an outsider to some of them. The closer you are to Havre, the less you will get of this, but as you get out towards the smaller towns further away from it, they have a little distrust for people they don't know.
The one other thing to expect is to be talked to by Border Patrol. Much like the locals, they notice when something is new or out of place. My cousin married a guy who is originally from a little town to the east of there. Even he gets stopped when he goes back to visit, because his license plates are from Helena. It won't be a problem, the agents are all decent people, just don't be surprised when they want to talk.