The story of animals surviving one of the harshest seasonal changes on the planet continues. As winter turns to spring, temperatures rise and Yellowstone bursts into life. Beavers feast on new green shoots, baby bison take their first faltering steps and grizzly bear cubs emerge from dens to explore this new green world.

It is summer and the Yellowstone beavers have a new challenge. Will the young survive as the river dries up and the colony is forced to move home? As food becomes scarce, wolves have a surprising strategy to keep their pups fed and grizzly bears are unexpected visitors on a cowboy ranch.