Sort of a cross between totally-stoked-Mountain-Dew-guys + farm-to-table-vegan-tatooed-hipster + do-not-really-have-to-worry-about-money + love-ridiculously-over-hoppy-ipas + own-four-bikes + sustainable-forever + into-outdoor-shaming-others [1].
I'm not that knowledgeable on demographic groupings but I think you know the type. Yes stereotypes are dangerous and I hope I don't offend anyone.
EDIT: btw to be clear I don't have any problem with above mentioned traits (as I'm not far from it myself). IMO I prefer it to the rural stereotypes I grew up with which is toting guns and killing animals for sport (which again sadly I don't actually have strong feeling against either). However I do hate IPA beers. The over hoppy beers have to stop (I'm stout, porter guy).
Also if you are looking for a similar city to Billings I just recently visited Flagstaff Arizona. Flagstaff is pretty darn cool.
[1]: https://stuffwhitepeoplelike.com/2008/01/20/9-making-you-fee...