In early fall, bull elk move out of the wilderness and Yellowstone Park to winter at the Federal Elk Refuge located under the Tetons in Wyoming. Sometimes, they migrate over 70 miles to reach the Jackson Hole Valley. During a clear day in early January, when the temperature was 25 below-zero, I was filming and noticed some late-arriving bulls moving into the refuge. They sometimes migrate over 70 miles to the Jackson Hole Valley. I was filming on a clear 25 below-zero day in early January and found late-arriving bulls moving into the refuge.