Elk belong to the deer family. Large bulls may weigh 800 lbs and have large antlers, which are shed annually. Cows are smaller and are without antlers.
Elk live in forests and forest edge habitat.
I found this elk just north of the Mammoth townsite in Yellowstone National Park. In fact, I first spotted him as he charged across the road from the townsite and up this ridge in pursuit of a cow elk that had strayed from his harem. I pulled over into a parking lot and jumped out of the car with tripod and camera. The vision for this photograph was already formed; I really wanted the moon in the photo with the bull silhouetted against the sky.