Every fall in the northern Pacific, up to a million salmon migrate back to the rivers and streams where they were born to spawn.

The crew heads inland to a section of the river to observe the many different families as they fish.

After seeing a wolf in the distance and tracks on the shore, the crew head inland in search of more clues to the wolf's whereabouts.

Casey and the crew go out in search of the family of the lost cub from the previous night.

Casey and his crew wander the tidal flats and interior of Katmai and find the bones of a humpback whale that washed ashore.