Beavertail Hill Campground

If you didn't make a reservation in advance don't bother even showing your face. I had been displaced by fires for 48 hours and couldn't make it to our other reservations so we were desperate for a place, stranded in Missoula. When we were trying to find a spot, the first open one we found was reserved for accessibility camping until 8pm. We stopped the car for literal minutes to walk and check the rest of the sites to see if anything was open and then we were going to decide if we wanted to hang out until 8pm or move on. Before we even had a chance, a vile, old, bald man on a tricycle approached us and started yelling at us, was completely unwilling to listen, cold, cruel, demeaning, and tried to ticket us... after literal minutes.

Cons:
Expensive - tents required to pay for hookup, so $40/night
Train runs all night, nearby crossing requires whistle
Highway noise
Pros:
Right off the highway, if you are desperate.
Clean toilets.