Firearm related is in 45-8-3xx
Can't carry in a place that serves alcohol for on premise consumption.
To carry concealed within the limits of a town or city you need a permit. If you are not in a town or city no permit required. Also concealed carry is considered 'on your person' so having a gun in a purse or 'off body' is not considered CC.
OC no permit required.
I don't think MT has full preemption or it wasn't grandfathered, there may be some local laws you should be aware of.
I am not sure about car carry.
Montana guys can give better info than me.