Mammoth cow elk closeup
Let me start by saying I did not approach this cow elk, it walked past my pickup. I was peacefully parked in front of Mammoth's Post Office when it strolled past. From the look in her eyes, I may have taken her parking space.
Actually, a bull elk had his harem of cows on the grass street divider in Mammoth. He was walking about, bugling and charging cars. Some of his cows were becoming bored and started leaving the divider to walk around the side of the Post Office. My pickup was in their route so they walked past on both sides.
Check out Roadside Nature Books for more information on Yellowstone's elk.