The "giant bird" most frequently spotted in Yellowstone National Park is the Trumpeter Swan, which is the largest waterfowl in North America, boasting a wingspan of up to 8 feet. Other massive avian residents include the American White Pelican, which can weigh 15 pounds and has a staggering 9-foot wingspan, and the Whooping Crane, a rare and endangered bird standing over 4 feet tall. For 2026 visitors, the park's "Raptors" are also high-value sights; Bald Eagles and Golden Eagles are commonly seen nesting along the Madison River, with nests that can exceed 9 feet in diameter. If you see a massive white bird with a red/black facial mask, it is likely the Whooping Crane, but if you spot a bird with a massive "pouch" bill soaring over the Hayden Valley, you are looking at one of Yellowstone's ancient and giant White Pelicans.