Yeah I love park. Unfortunantly, Montana is way behind in the park scene. I would say moonlight for jibs and big sky if you want anything resembling a decent jump.
There is a sketch double kink at irving school, a c rail at a church and a few down rails that I know of but you get busted really fast in bozeman. Last time we tried, the cops came before the jump was even finished.
last 3 urbans I remember no cops came and they went on for like 2 hours and the last one the cop told us to clean up when we were dun. There are a few good rails around now. I can't think of any off the top of my head but I have seen a few new good ones while riding.