Elk begin to become frisky starting in August.  Young bull elk may be seen chasing cow elk and trying to kill their calves (behavior observed August 2010),  

The cows and their calves gather just inside the west entrance and at Mammoth.  Wolves might also be seen near the west entrance, possibly even outside the park boundaries near the Grizzly & Wolf Discovery Center in West Yellowstone (www.grizzlydiscoveryctr.com/discovery center) just outside the west gate.

 young bull elk chases calf elk