We ate at two of the park's three lodges. They were pleasant and the food was actually pretty good so if you're seeing the park we can recommend them as an agreeable break in your day.
The park allegedly has a herd of about 1300 bison although we only saw perhaps a dozen. But there are also several types of deer, Rocky Mountain goats, pronghorn antelope and allegedly elk, although we never saw any signs of the latter. There are also a surprising number of wild turkeys and we saw a few turkey vultures and hawks.
There are donkeys descended from a group that used to haul tourists up and down the hills. They were released when the tourist hauling outfit went out of business and have become a feral herd that blocks the road and begs for food which the park personnel apparently do not discourage, quite unlike their attitude toward the feeding of the "wild" fauna.
You can drive the park's "Wildlife Loop" road just about any time of day and see a few isolated bison or pronghorns. But at about 6 PM, deer start appearing in astonishing numbers. Apparently the locals consider seeing deer about as exciting as seeing dogs and cats, but for us it was still pretty cool.
I am posting some representative photos of our tour of the park. Hope you enjoy them.