Well they could stop in Gardiner for elk and bison on the field. I'm sure they see an occasional bear, coyote, or wolf also.
In the 70's there was Elk sh!t on the field when we played in Gardner, main thing I remember is that the field was really hard, like it was almost on bedrock, was still better than West Yellowstone's which was literally in a cow pasture with cow trails and gopher holes included. Played there in a wet snowstorm once, just a muddy mess.