Sierra

Cruncher, a troublesome and elusive bear in Sierra National Park, harasses tourists and frustrates park rangers. Cassidy and Harper, aided by another ranger and the chief, rescue newlyweds Joe and Gail from a rugged spire which they have climbed, nearly costing them their lives. They climbed to flee from a park bear notorious for his harassment of tourists. The bear, dubbed ""Cruncher" by the rangers, causes no end of trouble and grief in the Park. Later, down in the park, Cassidy and Harper assist two campers whose car has heen attacked by Cruncher. After having scared the two campers sufficiently, Cruncher moves on to a group of garbage cans, knocking them over, creating confusion and making a mess. Cassidy loses his battle with Cruncher over the garbage cans and leaves to settle a dispute between two couples who have come to the park for a weekend.

This episode involves a doctor on a research project who unknowingly has a contagious deadly virus.