Can I be charged with DUI if I’m not actually driving my vehicle?

Yes.  Even if your vehicle engine is off, and you are just sleeping it off in your car, you can still be arrested and charged with DUI. You can be charged with DUI in Montana if you are driving or if you are in “actual physical control” of a vehicle. Meaning, if you are intoxicated and in your vehicle with access to the keys, you can be charged with DUI. 

How do I get home safely if I'm drunk?

Can I be charged with DUI if I'm under 21?