Yellowstone is in the midst of the annual “rut”.
That’s a polite term for fighting and sex.
The bison and the elk spend about a month or so each fall with this great distraction. The males get all pumped on testosterone and bump & crash into each other to determine who is the toughest and therefore has the right to breed with his choice of females. The females don’t seem to have a vote.
Notice in that last photo the little rider-on-the-rump….
We noticed two females waaay out in a field one evening that were unaccompanied…very rare during the rut. But then we realized there were two males in the woods on the other side of the road trying to cross in heavy traffic. They were right beside us, but moving fast. I apologize for this photo, because it was nearly dark and you can see the elk is running…but I wanted to show you the snow on his rack and how wet his coat was!