The Elk rut is in full swing and the bulls are working feverishly to gather their harem – and keep them together. This big guy had about 12 cows he had accumulated. However, a younger bull and another bull of similar size / age were encroaching and he was not a happy camper about it at all. Here he moves quickly to head off one of the interlopers. Taken this morning in the Moraine Park area of Rocky Mountain National Park, Colorado.