Montana State is a great school to go to if you're an outdoor enthusiast/skier. Big Sky/Bridger are both right there, and in the summer theres plenty of things to do like float the rivers/mountain bike/hike/rock climb/kayak..etc.
The girls? All of the girls that go to Montana State are super laid back skier/snowboarder/outdoors-y chicks. You're going to find a lot of hoodie-wearing, lets-go-camping chicks. Not very many prissy girls although you will find some in the sororities. Not the best place to go if you're looking for tons of "hot chicks". although it all depends on what you think is hot.
Partying is laid back, not really over-the-top ragers. usually hanging out at dive bars, throwing house parties, and planning large groups for camping trips is whats in store. as well as frat/dorm parties.
Classes are small for the most part and the teachers are really one-on-one. Easy to succeed as you can ask teachers questions/talk to them in between classes. rather than being lost in a robotic curriculum.