Hello from Montana!
My thoughts - I really, really, really like it here. For one, the town is in MOUNTAINS! Sure, they aren't quite like "my" mountains in Colorado, but they're the same general brand. The town is a good size (for me, at least). It has the conveniences of several grocery stores, a Walmart, a Target, several local restaurants and a few fast food chains. It also is large enough (for the area) to get live music about every weekend and in the summer they have a farmer's market. Supposedly public transportation is pretty good (although parking at the uni is horrible). For housing I could live in grad school housing or rent in the town. And there's tons of outdoor stuff to do in the area. Plus, Glacier National Park is two hours away and Yellowstone is five hours.
The chem department is small, but they say this means that everyone actually knows each other. Of the four professors I talked to today, two of them are working on projects in the field of environmental chemistry...and each of those two I could see myself working with given both their projects and their personalities. In addition, when I talked to the head of the grad department, he suggested four other professors (one in the geology department) that I might want to work with and arranged for me to meet with a current grad school of one of them today (he's on sabbatical right now). So it looks like I would have at least three (and up to six) professors who I think I would enjoy working with. The department has recently renovated its labs, so everything is nice and shiny in the building. The department seems really chill and everyone was willing to talk to me and answer questions (I stuck around the department 45 minutes longer than scheduled because I was talking to a grad student).
Cons when compared to WSU - it is a small department and funding is hovering around adequate. My stipend would be about 5K less than it would be at Washington State University...although only about 3K less once you take out the fees that I'd have to pay the uni at WSU. WSU's offer indicates that they REALLYREALLYREALLY want me - I got a research assistantship and most grad students get a TA their first year. WSU has a few more instruments and is probably a little bit more prestigious than U of MT. I could also learn how to run a nuclear reactor at WSU...not part of the package here at U of MT :-p
Pros when compared to WSU - I feel more like I belong here; I feel like I've gotten to talk to the profs more here rather than just listen to their prepared spiel on their research. People seem a lot less tense here than they did at WSU and while they definitely work hard and the average completion time for a PhD is 5 years (about the same as WSU)...they also have time to go hiking or skiing or tubing or...you name it. There are three profs that I definitely would be willing to do research with, as opposed to the one prof at WSU. It's *slightly* easier to get to than WSU from home and the town is bigger with more going on.
So I guess it's time to go back to W&M and mull this over. A decision will be difficult because the nature of my visits have been different: WSU's was their formal prospective grad student weekend - I was there with 24 other prospectives and we were wined and dined, but pretty much shepherded between events. At MT I'm the only prospective visiting this weekend...so although there hasn't been as much formal wine-ing and dining (I grabbed dinner on my own last night and then went out for drinks with my host student and some other students from the chem department, they took me out to lunch today, and then I had dinner tonight with my host student and some more grad students at her apartment). But the fact that I'm the only one here has meant that it's been a more personal visit. And then there's the difference in money. The cost of living in Missoula is slightly less than Pullman...but not that much. And if I were here, I'd probably spend money on going to national parks (at least occasionally) and camping...and I might "relearn" how to ski. But that would probably result in not being able to save much money... And there is the whole thing about WSU reallyreallyreally wanting me; that's flattering. I'd almost feel bad to not accept...
However, if I were to choose based on the "gut-feeling method"...then all of you should find some way to come visit Missoula, MT in the next 5 years.