As Corey, Lassie, and a young woman consulting with the Forest Service on landslide prevention aid a poisoned goose, its mate waits faithfully by.

Lassie races for help after an earthquake traps Corey under a tree in the path of an incipient rockslide, but the motorist who picks her up nets and drugs her, selling her to a vet conducting animal experiments.

A fire rages on a Western mountain range and, despite the efforts of helicopter crews, firefighters, and Lassie, Ranger Corey Stuart is trapped in the inferno. When a rescue team finally reaches Corey, he is seriously injured.

Severely injured from a raging fire, Ranger Corey Stuart lies in a hospital with Lassie keeping vigil by his side in this conclusion to a two-part series. When Lassie is given to a new Ranger during Corey's recovery, she journeys miles to return to his side.

Lassie, Scott, and their pilot Johnny assist an injured hunter trapped near a glacier.

While Neeka's father and Scott nurse an eagle that has become sodden from a fall in the lake, Lassie protects the bird's baby from a lynx.

Neeka must take charge when Lassie breaks a leg in a trap on a hike--and a wolf is stalking them.

After surviving a boat explosion that traps Neeka's father, Lassie braves icy waters to find Neeka and Scott.

A jaguar has been attacking cattle and the watchdog on a Western ranch, and Lassie arrives to help. She gets some unexpected assistance when a cougar, foraging nearby, hears the battle and attacks the jaguar.

Lassie stands guard over the injured watchdog as the jaguar and cougar battle. The jaguar retreats in defeat and Lassie recognizes the cougar as a friend from days past. Lassie summons the rangers to eliminate the hostile jaguar for good.

Ranger Scott Turner and a Scripps Oceanographic scientist, Diane Stafford, become trapped in a kelp bed during a deep-sea scuba dive. Lassie discovers their predicament and alerts Ranger Bob Erickson for the rescue.

Lassie twice comes to the rescue of a stray kitten that is first attacked by an angry hawk, then trapped in a cave by rising tides. The collie also finds time to retrieve a forest ranger's horse that has broken loose from his tether.

Two brothers are quarreling over ownership of a prize bull that they are entering in the 4-H show. They must resolve their feud, however, when the bull strays and is lost in the mountains, with a marauding mountain lion close by.

Lassie's day with Jingo on his master's construction site turns too busy: first she pulls the beagle away from a blasting site, then, in trying to get him out of a house about to be demolished, Lassie is herself trapped.

Bruno, a war dog under rehabilitation, suffers from flashbacks after being exposed to blasting and escapes from his run. Warning the construction crew and local ranchers that Bruno is dangerous, Lassie, Bob, and his trainer Mike then try to find him before the others do.

On a trek through the Oregon rainforest, Lassie and her master discover a careless camper who has leaked oil into a stream, endangering hundreds of ducks on their seasonal flight. The Ranger and Lassie teach the camper a conservation lesson he won't soon forget.

On a trek through the Oregon rainforest, Lassie and her master discover a careless camper who has leaked oil into a stream, endangering hundreds of ducks on their seasonal flight. The Ranger and Lassie teach the camper a conservation lesson he won't soon forget.

Bob and Lassie visit the wild, surf-tossed Oregon coast where logs washed downriver into the bay are creating a problem, where they meet Jake Peterson, an old acquaintance of Lassie, a former forest ranger who now is a crab fisherman. The logs prove even more dangerous next day, when Jake takes Lassie out fishing with him.

Huddled together in his disabled boat, Lassie and injured Jake Peterson ride out the tumultuous surf. But as the boat heads for the Cliffs, Bob and the Coast Guard begin a highly dangerous rescue.

A boy's camp is in danger of being disbanded when a wristwatch is stolen from a camper at the swimming hole. Lassie unravels the mystery, however, when she discovers the thief not another camper, but a pilfering crow.

Lassie befriend Patricia Prescott, who refers to herself as ""Walden,"" a free-spirited teenage girl, who has left home to live in the wilderness like her idol, Henry David Thoreau, after the young woman cleans up a picnic area. But both of them are endangered by aftershocks from an offshore earthquake.

Lassie leads the search for a tiger that escaped while en route to the zoo. The frightened animal is on a rampage.

Scott and Lassie stay with Neeka and his dad Dean Chalmers for a couple of days, and Neeka has the weekend to finish a biology report. While collecting leaves, he and Lassie meet Mr. Bowers, a lonely man who limps due to an injury and has turned his back on society. After Lassie and Neeka uncover Mr. Bowers' scientific knowledge and help him when he is hurt, Mr. Bowers realises he wants human company after all.

Scott, Lassie and Neeka camp overnight in an old mining town that is haunted, according to legend, by a wolf and a man. Despite Scott's assurances there are no ghosts haunting the town, Neeka and Lassie hear strange sounds and see things that have even Lassie spooked.

Neeka tries to drive his father's truck, which subsequently catches fire after bumping over a rock, and explodes in a ball of flame. Three terrified horses nearby break out of their corral and run off. After Neeka, Lassie and Dean put out the fire, they find the horses, including Neeka's horse Cloudy, who has been hurt in the escape.

Lassie helps two flying squirrels find a new home.

Moonshiners set up operations on national forest land. In an attempt to outwit forest rangers, the moonshiners set a fire. Tragedy results as the fire spreads and Lassie must come to the rescue of the moonshiners who become trapped by flames.