Journey with Kirk Johnson to Yellowstone, where wolves, grizzlies, beavers and Great Gray owls survive one of the greatest seasonal changes on the planet. As the temperature swings 140 degrees, cameras capture how the animals cope.

Episode Three: Find out why a summer with soaring temperatures could pose a threat to Yellowstone’s ecosystem. Learn if the Great Gray owl family survives a major fire in the Beartooth Mountains and see how one particular wolf pack is feeding its 11 pups.

Thursday, July 6, 2017, 9:00-10:00 p.m.