Sergeant Preston must work to clear King's reputation after a murderous claim-jumper falsely (and publicly) accuses the dog of causing a prospector's death.
A greedy trapper incites an Eskimo uprising and murders an honest Hudson's Bay factor as part of a plot to monopolize the supply of valuable silver fox furs.
The death of an Indian brave leads Sergeant Preston and King to investigate whether sabotage could be the reason for a series of "accidents" that are plaguing the Hog Back Mining Company.
Law-abiding Jim Carver reluctantly offers forgiveness and assistance to his brother Harry, a treacherous ex-convict who is wanted by the Crown for the robbery and murder of an aging trapper.
A self-serving Chilcotte medicine man further endangers his diphtheria-stricken tribe by convincing the chief to reject serum treatment in favor of carrying out superstitious rituals and taking Sergeant Preston as a hostage.
When gold thieves implicate an aging and reformed ex-convict in a robbery, the old man's last best hope for vindication is the unshakable faith of a little girl.
To avert a panic in the mining community of Last Chance, Sergeant Preston and King must move quickly to capture three thieves who used a diversionary tactic to hijack a wagon carrying a gold shipment and a cash-rich mail delivery.
Aware that he is suspected of misappropriating gold-rich land, a corrupt gold commissioner schemes to cover his crimes by murdering his replacement.
Two thieves steal a coded letter disclosing the location of a fortune in gold, but they find themselves on an ironic quest to find a Bible when they learn that the code involves specific passages in the Scriptures.
Ruthless gold thieves target a rich claim that was reportedly staked by "Windy" Brown, a man with an understanding wife and a reputation as an incurable teller of tall tales.
A mendacious investor attempts to gain control of a valuable mine by killing one of its principals and framing the other for the murder.
Claim jumpers Hunch and Shanto are determined to steal a valuable mining claim document that has been concealed inside the violin of itinerant musician Jim Dallas.
Recently orphaned Denny Pickens finds that his Aunt Flora is unreceptive to taking him in, but he gets a chance to prove himself by helping Sergeant Preston in his pursuit of bank robber Cris Darby and his smooth-talking brother.
Sergeant Preston and an overconfident Scotland Yard Inspector trail a fugitive murderer into a wilderness area inhabited by a crazed and bloodthirsty wolf.
An aspiring news photographer with a curious knack for being in the right place at the right time helps Sergeant Preston and King in their pursuit of fur thieves who were responsible for the death of an Indian brave.
Reformed ex-convict Luke Reading is accused of masterminding a series of robberies by a gang of hooded thieves, but he becomes Sergeant Preston's ally when evidence begins to point in another direction.
A ruthless member of a gambling syndicate attempts to affect the outcome of the All-Yukon Dog Race by assaulting the owner of the favored team and attempting to poison his lead dog.
Sergeant Preston offers help to an inexperienced young couple while pursuing thieves who have tapped into the RCMP's telegraph line in order to obtain confidential information concerning gold shipments.
Treacherous sneak thief Milt Strang is saved from freezing by compassionate Yukon newcomer Eileen Mabry. Strang repays the young woman's kindness by attempting to steal her husband's valuable gold claim at gunpoint.
Sergeant Preston must act quickly to prevent a lynching when struggling miner Johnny Johnson is falsely accused of murdering the man who held an overdue note on his claim.
In the Alaskan town of Skagway, Sergeant Preston is assisted by U. S. Marines in his dangerous undercover pursuit of a murderous fugitive and the head of a gold smuggling ring.
After looting a trading post and murdering the owner, two savage profiteers use the stolen food to extort gold from the starving inhabitants of a successful mining camp that was stranded from its supply chain.
While searching for a missing university professor, Sergeant Preston and the professor's son are taken captive by Kutchin Indians and face execution unless Yukon King can quickly find evidence that the Kutchins' "Totem Spirit" is a fraud.
An aging miner finds a rich lode with the help of his newly-acquired English partner, but the sudden wealth makes him the target of his envious brother-in-law and a murderous claim jumper.
Attempting to be the first to reach a new gold strike, greedy prospectors assault a trail-wise competitor, steal his coveted food cache, and cruelly leave him to die from wolves or exposure.
The abusive young widow of an elderly mine owner conspires with thieves to conceal the fact that the deceased man's gentle teen-aged granddaughter may be the rightful heir to his estate.
Concerned for his mother's safety, young Jimmy Greenwood leads murderous fur thieves on a dangerous chase over treacherous and little-used trails with Sergeant Preston and Constable Malloy in close pursuit.
A dishonest promoter with a disdain for "Fancy Dan" boxing rules schemes to abscond with the proceeds from a heavily-attended fight in the remote mining town of Wheelers.
The pusillanimous son of a crusading local newspaper publisher discovers his courage after he is abducted and threatened by the henchmen of the corrupt town boss and his dishonest attorney.
When a greedy mining executive files an unwarranted lawsuit against the claim of two brothers, his debt-laden son convinces one of the brothers to assist him in robbing his father's gold shipment.
A dishonest troupe of traveling performers plans to frame a former war hero for the theft of $17,000 in contributions intended for the families of the American servicemen who died as a result of the explosion of the U.S.S. Maine.
Constable Lee Wayne questions his own qualifications to serve as a Mountie when the brother of his fiancée is involved in a bank robbery and Wayne is unable to take the actions necessary to prevent his getaway.
Mine owner "Windy" Brown's braggadocio and his exaggeration of the size of a gold shipment put Sergeant Preston and King in danger from a pair of sneak thieves.
Yukon King's "lame dog" trick helps Sergeant Preston get close enough to reason with Tom Elders, a gentle veterinarian who turned into a rifle-brandishing hermit after apparently being swindled out of his life's savings of $9,000.
Sergeant Preston is close behind as young Constable Dennis Burns doggedly pursues murderous Lefty Burke across rough country, unaware that Burke is actually his long-absent father.
After his Eskimo tribe saves two white men from from freezing to death, tribe leader Ooluk vows revenge when the two decide to repay the kindness by stealing furs and assaulting Ooluk's wife and brother.
Released after 10 years in prison, psychopathic Carl Stack holds Sergeant Preston responsible for his incarceration and hires assassin Pierre La Fitte to murder him from ambush.
Sergeant Preston takes an interest when a young boy and his dog are both rescued from potentially life-threatening injuries by a man who may be a fugitive from justice.
Sergeant Preston searches rough and uncharted country for a lost party that was delivering a vital Indian treaty, but he is unaware that his "guide" is actually a saboteur who strongly opposes the treaty.
Sergeant Preston and King go on a determined mission to remote Herschel Island after receiving word that violent mutineers from a stranded whaling vessel have virtually enslaved the peaceful Eskimos who inhabit the area in winter.
Sergeant Preston poses as a cheechako in an effort to expose a pair of murderous thieves who dress in eerie all-white outfits to ambush (and frequently kill) would-be prospectors to steal their supplies.
Treachery abounds as a wealthy man's business manager murders a jewel thief in order to obtain the "Eye of Evil", a $100,000 black pearl that was stolen in the U. S. and smuggled into the Yukon in the hope of finding a buyer.
Two thieves who robbed an elderly miner meet Sergeant Preston on the trail and attempt to arrange an "accident" when King repeatedly sniffs near the stolen gold.
Bank robber Walt Daniels endangers his ex-wife and young son by returning to their home after telling his violence-prone partner Harry Evans that he must meet Daniels there in order to claim a share of the stolen money.
Sergeant Preston and a U. S. Marshal trail a ruthless bone-crushing bruiser and two henchmen who are stealing tobacco in Alaska and smuggling it across the border for sale in the Yukon.
A witness to a murder refuses to identify the killer. Will Sergeant Preston be able to solve the case?
Preston is aided by a disgraced doctor and his wife, while pursuing an escaped prisoner from California who wounded another Mountie.
Sergeant Preston is injured and shares a cabin with a madman near Fishing Lake.
Hyde and henchman Ram intend to take over Walker transport business. Grandpa El and Billy Walker plead for time as selling valuable pups will clear the debt. But violence occurs and Sgt. Preston chases the culprits to the Canadian border.
Two brothers are at odds with each other after the death of their father. Disagreement over a gold mine fuels their fighting. When a charred body is found in their burned cabin, the surviving brother is arrested.
Winter in the Spruce Valley gold mining region, brings unrest between the natives and the miners and loggers. Chief Taranga is on the warpath. Can Sergeant Preston keep the peace?
Preston enlists Yukon King and a blind Husky on the sled team to track down two cold-blooded killers.
While at Last Chance on a routine patrol, Sergeant Preston investigates the theft of little Jimmie's dog, Sarge.
John Fletcher is the victim of attempted murder by partner Borneo in a mine cave in. Sgt Preston is asked by the Fletcher children to investigate. Nirana's Indian friends rescue John and Preston with Yukon King go after the bad guys.
Sgt. Preston is helping Father Michel establish a home for Indian orphans in Gold Flats but trouble is afoot. Brand and Braddock intend to frame rival Donovan for theft. Preston, Yukon King, and the children work together to solve the crime.
Sgt. Preston travels to Goldport to discover the source of counterfeit currency. He goes undercover as a prospector and with Yukon King's help starts working on the case which puts his lady friend Sherry in danger.
An old man who tells tall tales of courageous exploits to his grandson is humiliated when he is robbed of his gold at gunpoint in front of the boy. He helps Sergeant Preston capture the robbers to win back the boy's faith in him.
A man who grew up in Georgia during the U.S. Civil War suffers a knock on the head during a robbery, causing him to think he is back home during Sherman's devastating march through the state.
Two bank robbers arrive in Hudson Bay and lay low. Sergeant Preston and Yukon King go to Hudson Bay on an unofficial tip to find the robbers.
Sergeant Preston and King are in Skagway, Alaska to deliver mail to an outpost set up for mounties. Though he lacks official jurisdiction, he is helping clean up the town of lawlessness, and is helped by a tenderfoot from Texas, after helping the man avoid being conned.
Sergeant Preston once again infiltrates a counterfeiting gang, one he also suspects of murder. One of the members is an enormously strong but simple-minded man. Old Faithful, the murder victim's lead dog, joins the sled team.
An explorer who fakes a claim of finding a sea passage to the North Pole uses sabotage and trickery involving small skull stones to keep from being exposed as a fraud. He is willing to commit murder if necessary.
A man who along with his wife wants to move back to the United States is targeted for murder so the would-be killers can take his mine. Sergeant Preston and King help fool the would-be killers into thinking the man is dead in order to trap them.
Sergeant Preston is on the hunt for an escaped killer whom Preston helped put behind bars. The killer mercilessly gunned down another mountie and friend of Preston's, and is out to kill Preston.
A trigger-happy old man's imaginings of people trying to rob his gold mine turn out to be right.
Miners are being terrorized by three robbers clad in black, led by a well-liked woman.
A fur smuggler is coercing a woman, whose father has a weak heart and could die at any sign of excitement, into supplying him with furs to smuggle across the border.
A family man whose son needs an operation is accused of stealing gold that he was safeguarding. An aging malamute aids in the pursuit of the real thieves.
Two gold robbers firing shots from a ridge have Sergeant Preston pinned down in a cabin with two other men, one of whom is a washed up doctor paralyzed by fear.
Two ex-convicts try to blackmail a former cellmate into giving them the money out of the safe at his trading post. Sergeant Preston and King get help from a St. Bernard.
Two murderers escape jail and steal Sergeant Preston's sled team. Burdened with an inferior team, he sends King out to find his own team and lead it, along with the killers, back to him.
A young man tells the news papers where is gold strike is and now claim jumpers are out to get it.
Sergeant Preston is on the trail of fur thieves. He gets help from a reclusive oaf named Grizzly.
Sergeant Preston must find the man who attacked a prospector and attempted to steal his diamond necklace before the would-be thief tries again.
Two hold-up men - one wounded - force their company on an old ex-convict friend who is now going straight. They threaten to reveal his past to his young daughter unless he helps them by getting medical aid.
After critically wounding a young mountie, three outlaws steal his gear and supplies, including his uniform, allowing one of the criminals to pass himself off as a mountie.
A man comes to the Yukon from England to have his young cousin, a boy, killed for the boy's estate, and is aided by three outlaws.
A man is murdered and his dog is the only witness.