July 2015 we did some camping in the Two Medicine campground in Glacier National Park.
Two Medicine campground is a great hidden gem in GNP. The big challenge, Two Medicine is a first come, first serve campground. I'm going to share some secrets here on how we secure sites 100% of the time when we visit.
Here's the secret: The evening before, we find sites & speak with folks leaving in the morning. We arrive early the next morning. The camp host usually pull the tags off the post by 7:00 am, however you can fill out your CG slip and slide it underneath the receipt of the current site holder. I will approach the owner of the site if I see them milling around to break camp. They are usually good with you leaving a chair around the fire, be polite, stay out of their way and try not to encumber them. I then return to my parked rig off to the side and wait for them to leave. As they pull out, I pull in.
This has been a successful strategy for us, share your own strategies!