I heard about one person kicking a bison to get it to stand up, and getting gored to death.
True or not, sounds like a Darwin award. Not a smart thing to kick any
animal, yet alone a bison.
Sometimes, though, you can get a lot closer to an animal in an urban setting. I've gotten to within 3 feet of a Great Blue Herron, and followed other GBH's around as they fish. I've seen more deer here at work at 20 feet away than I have in the wild all my life from 50 feet away.
Keep in mind, most animals do not hurt humans unless provoked, startled, interrupted, or protecting their young. Because you can't learn the behaivor of a tenth of the wildlife you'll come across, you'll be best off using common sense. If they have young, respect them a little more. If they don't see/smell/hear you, that's great for your pictures, but be forewarned.
Keep a safe distance from elk and moose, who will commonly choose to attack since they travel in herds. Deer typically will run away. I don't know much about bison or bear behaviors - is it brown bears that are more aggressive than black bears? Larger bears can behead you with a claw.
Foxes, coyotes, and wolves will typically run away. Wolves are portrayed as vicious, but if you see one you'll be fine. A pack, be more cautious of.
Most smaller animals (beavers, raccoons, ...) will typically run away, too. However, raccoons are vicious fighters, so don't push it if you see one!
I hope this was somewhat helpful. Sounds like an awesome trip!