Here's some links for the prairie, if you ever get a chance check it out someday. There are quite a few bison there, but the best time of day to see them is at sun up or sun down. We saw quite a few deer out there as well, I don't know if there are elk out there yet or not.
I can't wait to go back, I want to take better and more pics of the buffalo. I have plans to return this winter, after it's snowed to take pics as well. Prairie City isn't far from here, it's a nice drive.