Bighorn sheep are among Yellowstone’s most agile and iconic animals. From their massive horns and cliffside agility to dramatic headbutting rituals and vulnerable populations, this edition of Creature Feature Fridays explores their unique adaptations, challenges, and the vital role they play in the Greater Yellowstone Ecosystem—featuring stunning photography by Julia Cook.

Discover grizzly bear facts, from rare five-cub litters to the story of 399—Yellowstone’s icon. Featuring photos by Julia Cook Photography.