As much as I loath the idea I’d probably go either as a lion, a scarecrow, a tin woodsman, a witch, or a small dog. No way am I going as a farmgirl.
No winged monkeys?
I’m from Florida, so I’ll just dress up as a huge wang.
The obvious choice would be a cowboy, but even though I think Montana is the archtypical cowboy state, that could also be anywhere in the West. Likewise grizzly bears or bison. No, the best choice would be either a tyrannosaur or a triceratops, both of which are (were) found almost exclusively in Montana. And were also my favored choices for our state quarter, but no, we had to go with a completely non-distinctive steer skull instead.
Alabama. I’d go as a box of crackers with a thick red (for red-state) belt that has a Bible for a buckle.
If not a cowboy why not dress as a “Montanan” by transplant (e.g., the person that moves to Montana and thinks they are a “Montanan” just because they have a new zip code.)
Dress just a little too well for any ocassion. Bonus points if you wear a new cowboy hat, triple points if it’s pink or purple and you aren’t actually in a rodeo wearing a sash.
Nah, that would be a Californian.
To be fair, I’m a Montanan by transplant myself… I mostly picked Montana rather than my home state of Ohio for this because Montana has lower population, so I figured that Ohio would be well-represented by others. For Ohio, though, the obvious choice would be a Buckeye, that being the official state symbol and nickname. One could also go with a uniform for one of the pro sports teams.
Ooooh, MUCH better choice!
I’ll pin artificial flowers all over my dress and go as Victoria: The Garden State. It’s easier than trying to dress up as Zach Braff.
And then I’ll get beaten up by all the other states who call themselves the Garden state. Chill out, New Jersey!
I’ll just ask all the women and children in my neighborhood to go with me as a polygamist family.
Not really, but it might be fun…
Queen Califia.
I’d have to go hit the tanning booth a lot to make it work.
The unofficial nickname of Tokyo (which counts as a state) is The Concrete Buttplug, so I guess I know what I’m going as.
Ontario: we’ve got ‘rocks and trees and trees and rocks and rocks and trees and trees and rocks and rocks and trees and trees and rocks and… waterrr…’ 
So I guess I get a choice.
Seeing that Alaska driver’s license in my wallet, I must, MUST put on a red one-piece swimsuit. As a large man who resembles Grizzly Adams, I may not win Miss Alaska 2008 though.
Chefguy, beat ya to it!
Ralph: “I’m Idaho.”
Now I have an image of you from NSFW photo thread as The Thinker in a cowboy hat.
I’m from Texas. Since going as an actual asshole violates the rules of this thread, I guess I’d dress as an oil derrick?
I could just crochet a giant mitten to put over my head.
Exactly what I was going to say, right down to the link! Alternatively, Wisconsin is the Badger State.
You could make a big print of one of CM Russell’s more famous paintings, and wear it on a big sandwhich board?
Tristan- transplanted Montanan living in Pennsylvania by way of California. Sort of.
I could just get quietly shit-faced.
(South Australia, The Wine State).