Pure white Dall sheep are seen in the mountains of the Brooks Range. They are the only wild white sheep in the world. They are part of a new world species called Thinhorn sheep. The Dall sheep blend in with the snowy environment they live in. They usually keep to the open places above treeline. They can be seen climbing the narrow ledges and ridges of the mountains. During spring and summer they frequent mineral licks along the banks of streams and rivers to resupply themselves with nutrients they lost during the long harsh winters.

The ewes have their lambs in May and June in the lambing grounds which are protected by steep cliffs. They stay there until the lambs are old enough to travel. Wolves are a predator of the Dall sheep.