Bruno is a war dog undergoing rehabilitation. When blasting occurs nearby, he panics and escapes. His trainer Mike warns all parties that Bruno is dangerous, then sets out with Bob and Lassie to find Bruno before anyone else can.
Archers begin hunting Bruno after he stampedes a corral of horses and kills a calf. Lassie finds Bruno and tries to lead him home. Then Buck is thrown from his horse and Bruno has a decision to make: will he attack or not?
On a trip to the Oregon coast Lassie befriends a mallard and her ducklings while Bob surveys a potential campsite. Danger lurks nearby in the woods from an unusual source.
While Bob tries to protect dunes from erosion near a lake at a dune buggy track, the club's pregnant dog Lady looks for a place to deliver her pups but ends up having them in the midst of the raceway. Lassie must help her.
While Erickson is assessing the danger caused by timber washed away by a flood, he allows former ranger Peterson to take Lassie on his boat to survey crab cages where Peterson is knocked unconscious with a storm approaching.
Newly conscious Peterson due to rough seas, timber debris and his condition cannot prevent his boat from drifting toward cliffs but Erickson drops seaward from a helicopter to contact a rescue boat which saves Peterson and Lassie.
The success of a camp for Job Corps volunteers is threatened when a crow steals a congressman's son's watch and implicates one of the volunteers, a former delinquent trying to turn his life around. Lassie must reveal the truth.
Lassie befriends a free-spirited young woman who calls herself "Walden" in homage to her idol, Henry David Thoreau. Aftershocks from an offshore earthquake endanger both Lassie and Walden, especially when Walden takes refuge in a cave.
It's a typical day for Lassie and Scott with the collie being interested in nature and it's wild creatures. But an Asian tiger being transported escapes and it's up to Lassie with her friends to locate the big cat before it does harm.
Scott and Lassie visit Neeka who takes Lassie with him to help collect and identify plants for a school project. They meet Clay Bowers, whom Neeka asks for help with his project partially to draw the unhappy man out of his shell.
While surveying riding trails, Scott, Lassie and Neeka camp out in a hotel in a deserted town supposedly haunted by the spirits of a wolf and the man who killed him. Many sounds including a wolf howl upset both Neeka and Lassie.
When Neeka's dad comes to town, Neeka decides to drive his truck. Although he and Lassie escape harm, the truck isn't so lucky. It. crashes and leaks gas. The resulting explosion frightens the horses and Neeka's own horse is badly injured.
Lassie meets a pair of flying squirrels. When one becomes trapped in a can, the mate seeks Lassie's help. The trapped squirrel is chased by a hungry coyote and then rolls down a cliff with Lassie and its mate following closely behind.
Two moonshiner brothers move into the Clear Lake National Forest in order to make their product undisturbed by the law. When ranger Bob catches Woody buying suspicious supplies, Leroy decides to distract the ranger by setting a small fire.
A man pursuing wolf bounty shoots a wolf in protected territory and then watches Erickson and Turner nurse the wolf back to health with help from Lassie who uses the creature's paternal instinct to gain recovery.
Bumbling Job Corp worker Cal Baker is prevented from dropping out by the inspirational words of a fellow Job Corp worker and the successful rescue of that fellow Job Corp worker when a crisis occurs.
A pet chimpanzee of a man who lives near a massive project site leaves the house and wanders into various dangerous aspects of the construction with Lassie in a pursuit of concern.
When Allan surveys an old Air Force bombing range to develop as a grassland, his helper, who is partially buried by a landslide, dislodges an old unexploded bomb which Allan must disarm via remote instructions from the ranger station.
Lassie attempts to rescue a fawn that has become trapped in a vinyl reservoir that is part of an experimental water system constructed to rescue the cattle business of a lady rancher that leases from the forest service.
When pilot Bert, Scott and Lassie crash land a helicopter in the snowy wilderness, a search ensues by air and snowmobiles operated by Bob and Mark who are lead to the crash site by Lassie.
Scott intervenes to correct the a father and a son relationship which has become dysfunctional after the mother's death and has caused the son to shun school and take careless actions with firearms.
Neeka spends his vacation with Lassie, Scott and Bob at the Roaring Camp spur line which will run through the redwood forest. There they befriend a little chick who continually wanders into trouble.
Bob and Neeka must nurse Lassie back to health when on a camping trip she falls into freezing rapids while she and Neeka are assisting a nesting crow in danger.
Manuel Sandoval crosses the Mexican border into the U.S.to receive the blessing of the animals at a mission to keep a promise to his little sister that their deaf dog will hear by Christmas.
Scott, with Lassie, joins Park Ranger Ivan in flying over Superstition Canyon discussing local legends. They locate a hardy prospector Hobart who has appendicitis. Lassie is left to take care of his burro Emily until Scott can return.