While many visitors come for the bison, the Elk (Wapiti) is actually the most abundant large mammal in Yellowstone National Park. In 2026, the summer elk population can reach between 10,000 and 20,000, and they are frequently spotted grazing in the meadows or even lounging in the lawns of the Mammoth Hot Springs area. If you include smaller animals, the Uinta Ground Squirrel and various species of ravens are technically more "common" in terms of sheer numbers. However, for "charismatic megafauna," the Bison is a close second, with a stable population of around 5,000 to 6,000. It is a peer-to-peer "safety essential" to remember that even though elk seem "docile" and common, they are wild animals; during the "rut" (mating season) in the fall, bull elk are notoriously aggressive and can charge at vehicles or people who get too close. Always maintain at least 25 yards of distance from elk and bison to ensure your Yellowstone adventure stays safe.