An evil ranch foreman tries to provoke a range war by playing two cattlemen against each other while helping a gang to rustle the cattle. Each cattleman blames the other for missing cattle. With the help of Bill Cassidy (Hop-along, because of an earlier bullet wound) and Johnny Nelson, the warring cattlemen join forces to do in the outlaws.

The grandson of the notorious bandit El Toro witnesses the murder of his parents by men trying to hijack the gold they were carrying. After El Toro saves the life of Hop-a-long Cassidy, Cassidy agrees to find and protect the boy, who is in hiding from the killers, whom he can identify. Cassidy and his partner Johnny Nelson, with the help of friendly bartender Spike, try to save the boy and bring down the man behind the gold robbery.

Rancher Arnold sends for Hoppy and Red to help fight the cattle rustler Nevada and his gang. Hoppy poses as a gambler to get on Nevada's ranch and meet the snuff taking boss who pictures himself another Napoleon. Hoppy's smoke signal alerts Arnold's men leading to a massive gunfight.

Ranch owner Sally Jordan is engaged in a fence war with rancher Big John Trumbull. Hoppy and Johnny, along with trusty sidekick Windy, side with Sally Jordan. They control a huge cattle stampede by using dynamite.

Hoppy returns to find Johnny in trouble. Buck Peters has been shot by Porter who made it look like Johnny did it. When Johnny flees he runs into Linda. He takes a liking to her only to learn her father Shanghai is one of Porter's gang. Going after Shanghai, he gets captured by the gang and Porter now plans to kill him. But Hoppy is near by and Johnny will get unexpected help from Shanghai.

An evil gang is involved in both cattle rustling and the robbing of stagecoaches. Hoppy must stop them without help from the sheriff who turns out be a major outlaw himself.

When a miner is murdered before he can file his claim, Editor Saunders sends for Hoppy. Now the new Marshal, Hoppy learns Lilli Marsh owns the murdered miner's claim and her henchman Blackie was the killer. After Hoppy and the ranchers take care of Blackie's gang, Hoppy goes alone to face Blackie and Lilli.

When Hoppy agrees to lead a large cattle drive north he runs into lots of trouble. First Anderson and Wilson join the drive to do what damage they can. Then Lewis and his men posing as Tail officials try to cut out part of the herd. When Hoppy sees through this ruse, they rustle some cattle and burn the camp.

Officials on both sides of the border are after an outlaw gang led by the Fox. They devise a plan where Hoppy is supposedly kicked out of the Rangers to become an outcast. When the Fox shoots his own gang leader, the famous ex-ranger Hoppy is recruited to replace him. Hoppy eventually realizes that the Fox is posing as the town idiot Loco. But the Fox is also on to Hoppy and uses Windy and little Molly to set a trap to for him.

The ranchers are having their cattle rustled and it looks like Indians from the reservation are responsible. Hoppy captures rustler Lone Eagle only to have him shot before he can talk. The Indians capture Hoppy thinking he was the killer. But Hoppy tells the Chief that Ranger Andrews is the rustler and probably killed Lone Eagle. If he can be allowed to retrieve Andrew's gun, the bullets will match.

Hoppy arives posing as an outlaw to avenge his brother's killing by Plunkett. After robbing a train and killing Plunkett, he gets to meet the boss known as the Lone Wolf and lead his next job. Seeking help from Stoneman to capture the outlaws, he realizes too late that Stoneman is the Lone Wolf and is captured.

Hoppy clears Lucky on a charge of bank robbery and foils the plot of a crooked lawyer to rustle a herd of pedigree cattle and take over the valley.

On a cattle drive Hoppy, camp cook Windy, companion Lucky, and young Artie Peters encounter an eccentric professor. The professor professes to be searching for the evolutionary missing link, but in reality he is a cattle rustler who uses his dynamite to scatter the cattle in order capture some of them.

The Army needs 500 horses and Hoppy has been sent to round them up. After he and his men do all the work, Carson arrives and plants ten of his branded horses among the group. Then he and his men arrest Hoppy and his crew for rustling and make plans to hang all of them and then sell the horses.

Lorna Drake arrives from England to take over the ranch. Although she and Hoppy argue most of the time she takes a liking for Hoppy, angering her fiance Ronald. This enables Scar to enlist Ronald's help in his plan to kill Hoppy. But when Hoppy foils that plan a forest fire develops endangering Lorna.

Hopalong Cassidy, boss of the BAR 20 ranch in Texas, rides down the New Mexico cattle country in response to an urgent message from his lifelong sweetheart, Nora Blake, who is in serious trouble. Before he, "Lucky" Jenkins and Pappy can reach her ranch, they are stopped by Clay Allison, a cattle-rustler who is in almost complete control of the district, and wants to extend his holdings by seizing Nora's cattle and driving her out.

Belle Starr has just returned from prison to take over her ranch where her foreman Ringo who is rustling cattle. He is after the herd and has planted his man Twister there. When Hoppy finds the cattle stampeded by Twister, he secretly marks them hoping this will lead him to the rustlers and their buyer.

Hoppy's friend Dennis owns a rich gold mine. Frazier who owns the adjoining mine and wants the Dennis mine, has Dennis killed. Hoppy steps in to take over running the Dennis mine and learns Frazier's men sneak into and work the Dennis mine at night. Hoppy captures one of Frazier's men only to be captured in return by Frazier and left to die in a burning building.

Caldwell and Nixon have their men rob the stage and then critcize the Sheriff for not catching the robbers. With her father the Sheriff under pressure, Mary sends for Hoppy who finds the stolen money and sets a trap to bring in the entire gang.

Some years before, a vicious criminal and master of disguise known as 'The Fox' is captured by Rurales Colonel Gonzalez and Hoppy working undercover. When 'The Fox' escapes from prison, he vows to exact vengeance from the two lawmen. He lures Cassidy south of the border with a forged letter from Gonzalez and murders Gonzalez in cold blood. Aiding 'The Fox' in his plans is his sister Janet, to whom the chivalrous Hoppy finds himself attracted.

The local school is causing Hoppy problems. First Bar 20 cattle are stolen when Hoppy investigates a problem there. Then the new teacher arrives and disrupts the routine of the Bar 20 hands. Later with the Bar 20 hands at graduation, the rustlers are poised to strike again. But there is dissension among them and this will lead to the break that Hoppy needs.

Keller buys Marsh's cattle and then murders him to retrieve the money. But Ann Marsh remembered some of the serial numbers and this is the clue that Hoppy needs. He arrives posing as a dude. He also poses as a novice poker player and this brings in a few of the stolen bills. When he realizes Keller is the one he is after, he wins back all the money at the poker table. He escapes from Keller's saloon but Keller and his men head out after him.

Hoppy goes undercover as a gambler from the East when Bar 20 cattle are stolen by unknown rustlers. Brennan/Talbot are twin brothers (one a casino owner, the other a rancher) and Hoppy believes they provide alibis for each other while one is out committing crimes. Hoppy gets a job in the casino to learn more but is exposed when a gambling gunslinger notices him.

Town Marshal "Windy" Halliday sends for his old Bar-20 Ranch friends, "Hopalong" Cassidy and "Lucky" Jenkins, to help fight a gang of outlaws led by "Stiff-Hat" Bailey. Cassidy becomes interested in Mary Joyce, whose ranch is the main target of the Bailey gang. Things are complicated by the fact that Mary's husband, "Rusty" Joslin, and escaped convict, is tied up with the outlaws.

Having to herd their cattle over Buck Collin's land, the ranchers are building a railroad spur to avoid paying his fees. To stop them Collins has him men rob the stage of the payroll money and also disrupt the construction. But Hoppy has a plan. He lets the Deputy know when the stage will be robbed and then he robs that stage. Collins men try to rob him just as the Sheriff arrives. When Hoppy breaks them all out of jail he is accepted into the gang.

Hoppy and Lucky deliver cattle to Valdez in Argentina. Merritt is after Valdez's ranch and has his son and daughter killed, supposedly in an accident. Examining the bullet, Hoppy suspects murder. Hoppy then remembers Merritt and finds his picture on an old USA wanted poster.

Marshal Hoppy has been called in to investigate payroll robberies and arrives posing as Marvelo the mind reader. When Lucky arrives Hoppy has him pose as the expected Marshal. Hoppy works his way into the gang led by Ma Burton and sets a trap for them. But once again Lucky slips up revealing the masquerade and Hoppy finds himself a prisoner in a burning building.

European bad guy Baron Bendor leads some local townsmen in a plot to obtain horses through theft. Hoppy and his sidekicks Lucky and Speedy must find and expose the horse thieves.

Hoppy and Lucky confront a gang of outlaws which has been ravaging stagecoaches and gold mines. The final gunfight is at Ed Colby's mine.

Hoppy, Lucky and Speedy are driving a herd of mustangs to the town of Blue Sky, where they are to be delivered to Jeff Chapman, the owner of the Bar 20 stage line, when they come upon Jeff's runaway stage. The stage has just been robbed by Smiley and his gang of singing outlaws, who have shot Jeff and left him to die.

After receiving a call for help from California Texas Rangers, Hoppy and new sidekick California Carlson head to California to help out Lucky Jenkins against a tough gang of land grabbers.

Stephen Westcott and Ed Martin scheme to put Jane Travers' wagon line out of business. They want to use it take over all the wagon- train traffic going west. Hoppy, California and Lucky must make sure that doesn't happen.

Joe Weller has instigated a conflict over water rights between two ranchers. The idea is to have the ranchers do each other in then move in and take over. Hoppy and the good guys won't let this happen.

With the local vigilantes unable to combat the lawlessness, Forbes sends for Hoppy. Dry gulched on the way, Hoppy realizes the bad guys were tipped off and he, Lucky, and California arrive posing as bad men. Hoppy suspects Logan and sets up a silver shipment to trap him. When the silver disappears, Hoppy looks like a double crosser and is trouble. Not only has his identity been revealed sending gummen after him, but Lucky is about to be hung as an accomplice.

Hoppy, Lucky and California search for a mine owned by Trudy Pendleton after it was taken from her by the swindling gambler Ace Gibson. They find the mine and Hoppy fights Gibson over it.

Belle Langtry runs a town being taken over by cattle rustlers. She is also a front for the outlaws, who are led by Steve Fraser. Hoppy gets elected sheriff and cleans up the town with help from the Bar 20 boys.

A former Bar 20 cowhand is now a cattle rancher and having trouble with rustlers. Hoppy and the Bar 20 gang ride in and surround the the bad guys. June Winters joins the posse and serves as the romantic partner for posse co-leader Lucky.

Brent's cattle are being rustled and he has sent for Hoppy who arrives with California and Johnny. The three pose as dude English detectives but their identity is quickly revealed when they have to fight off the rustlers. When Hoppy and California finally find the rustler's hideout they also find themselves prisoners.

Some Easterners intend to seize a tract of valuable timber land. Hoppy must try to stop them before they blow up a major dam.

Hoppy and his pals accompany the Grants to Saudi Arabia to buy horses. When the Karitga's have El Kader kidnap Charles Grant for ransom, Hoppy engineers his rescue. When they return to the Sheik's camp, El Kader and his men attack.

The usual gang of bad guys is out to grab up all the available ranch land. This time their object is land belonging to Chinese. As an aside, Hoppy leads some archaeologists through parts of California.

Hoppy is sent for to see if he can find the outlaw gang working both sides of the border. The gang leader, sometimes dressed as Hoppy and sometimes as Gonzales, has the two sides suspecting each other. But finding an old wanted poster, Hoppy sets a trap.

Burton is after Clark's ranch. He gets the banker to refuse to renew Clark's note and then sends his men to rustle his cattle. Hoppy is Clark's new foreman and is on to Burton's scheme. But just as he learns of the rustling and is about to go after the gang, the Sheriff arrives and arrests him for hiding Johnny who has been accused of robbery.

Sheriff Hoppy has to find a way to bring the bad guys, headed by Tom Jordan, to justice in the Lone Star state. The problem is that they are hiding out beyond his jurisdiction, in Oklahoma.

When three Texas Rangers try to investigate kidnapped Mexicans being used as forced labor in the mines of Silver Bullet, they are framed for murder by the town's corrupt sheriff.

In order to find out whether ranch owner Dan Slack might also be a cattle rustler, Hoppy gets a job on Slack's ranch. When he is discovered by Slack's crew, he is framed for murder.

While oil drilling, Hoppy and California discover an underground well - a potential threat to Jebb Hardin's monopoly on water in the region.

Mark Jackson has a scheme to get Adams' land. His gang robs Adams' fiancé of her jewels, robs Hoppy of his cattle money, and then gives that money to Adams to buy back the jewels in exchange for a deed to his land. But Lin recognizes the bills and Hoppy and his pals go after the robbers.

To obtain water rights, bad guy Mark Foster murders the heir to a cattle ranch and puts an imposter in his place.

When Hoppy's falsely accused young friend is killed while supposedly trying to escape from jail, an embittered Hoppy is blamed and drummed out of the Texas Rangers.

Maxson and Trimble are using the Night Riders to scare the ranchers off their land knowing there is oil under the ground. Finding a wounded lawyer Corwin, Hoppy assumes his identity. But Sam Nolan knows Hoppy and when he arrives in town the masquerade is over.

Julie's husband has been murdered and land agents want her to sign away her property rights. Hoppy warns against this but she does so anyway. It looks as though she will be unable to deliver the timber called for in her agreement. Hoppy has to make the lumber deal happened and solve the murder.

After Hoppy helps round up the Trilling gang, Trilling breaks his men out of jail and they rustle the Bar 20 herd for revenge. When Hoppy gets the herd back, Trilling posing as a Marshal not only gets the herd again, he gets the Sheriff to jail the Bar 20 gang. Getting help from the Sheriff's daughter, Hoppy and pals start out once more after Trilling.

When he runs for sheriff, Hoppy is beaten by Jerry Doyle, the gutless wonder voted for by every crook in town. When Hoppy moves to have the new sheriff impeached, outlaw leader Tad Hammond hires forty gunslingers to stop him.

Hoppy, California and Lucky must rescue Mrs. Evans from the corrupt sheriff and his black-hatted gang of outlaws.

At the request of an army officer friend, Hoppy goes to retrieve the officer's deserter son from an outlaw enclave where he learns the son is being forced by the ringleader to take part in scam to take gold in cavalry disguise.

At the reading of his late cousin's will, California learns the estate will be divied among whoever remains of the seven relatives. With one already dead, another immediately murdered, and the Lawyer telling them the ranch is almost worthless, Hoppy investigates.

Sue Harmon gets Hoppy and his friends to join their expedition looking for Indian artifacts. Expedition leader Atwood makes a deal with nearby cattle rustler Morgan to loot the Indian treasures instead and sell them. Hoppy is on to their plan and pretending to leave follows them. Not only is he outnumbered by Morgan's men, but California has himself about to be sacrificed in an Indian ritual.

With a storm approaching, Hoppy and his pals take refuge in a church in an abandoned town, When Riker and his men arrive to tear the church down, Hoppy kicks them out. Riker then has the church surrounded and those inside find themselves prisoners.

Hoppy, California, and Lucky travel to Mesa City for a short vacation. California buys new clothes and carrying his old ones in a suitcase, bumps into escaping bank robbers in the dark. His suitcase gets switched with that of the robbers and he is seen with the money. Hoppy must find the money that has mysteriously disappeared and also the robbers so that he can clear California who is now in jail.

After receiving money for delivering a large herd, Hoppy, California, and Lucky retire to an inn for the night. The next morning both Lucky and the money are gone. At first Hoppy suspects Blaney and his gang but later realizes Doc Richards is responsible. He and his mysterious concoctions have put Lucky under a hypnotic spell and Hoppy and California set out to find him.

Hoppy, California, and Lucky arrive at an inn for Lucky's wedding only to find it called off as Lucky's fiancee's uncle is missing. He is found murdered and on each of the next two nights a man is found missing the next morning. All three stayed in the same room and Hoppy has lots of suspects.

Lee Garvin has eloped with the daughter of a railroad man who didn't approve of the marriage. Hoppy steps in when the young man is framed for murder.

Teacher Lola Blair is against building the saloon right next to her schoolhouse. When she is kidnapped, Hoppy rescues her and forces the saloon keepers to relocate.

A banker is trying to cheat people out of their silver-rich land. Hoppy learns that the banker is in league with an outlaw gang.

Hoppy is an agent of the federal government investigating the counterfeiting of both U.S. and Mexican money. His only clues are the name "Mordigan" and a drawing of a comet.