Pirates on Horseback (1941)

As rustled cattle have mysteriously disappeared, Johnny sends for his friend Hoppy, Hoppy arrives and immediately suspects Dan Slack. Realizing his telegram about Slack was intercepted, he locks up the operator Lafe knowing he can escape. Tailing Lafe he finds a secret entrance to a mine and inside finds the missing cattle. But Slack's men also find him just as the cattle are stampeded through the mine shaft.

Belle Starr has returned from time in prison only to face a hail of bullets, along with rescue by Hoppy and the Bar 20 gang.

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.

The U.S. Army needs more horses for the Spanish-American War. Hoppy must turn his Bar 20 cowhands into Rough Riders to gather up the horses, and of course bad guys try to sabotage the operation.

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.

Hopalong Cassidy and Johnny Nelson ride to the mountains to help a man and his daughter save their logging business from someone who is sabotaging their efforts.

A crusading newspaper editor recruits his old friend Hoppy to take the job of Marshall in a town rife with vice and murder directed at helpless miners.

Before he was killed by Mark Foster's men, Bud Lawton willed part ownership in his ranch to Hoppy and his two pals. When the three arrive they find a fake posing as Lawton. When they expose the imposter, Foster gets the Sheriff to jail them for Lawton's murder.

When the outlaw El Toro saves Hoppy's life, Hoppy agrees to find his missing grandson.

An evil deputy is using Indian half-breeds to rustle cattle. This causes trouble between the cattlemen and Indians. Hoppy, Windy and Lucky see that justice is served. Songs abound.

Hoppy, Johnny and Windy are fighting a malicious gang trying to stop a cattle drive from reaching a drought-stricken North.

Tres guardianes de Texas, encabezados por Hopalong Cassidy, cabalgan a la vera de un río cuando descubren que un hombre mexicano acaba de ser abaleado. Una mujer les confunde entonces con los asesinos, y apuntándoles con un revólver, consigue llevarlos hasta la guarnición mexicana donde ellos rebelarán su verdadera identidad. Después, habrá alguien interesado en Silver Bullet en convencer a todo el mundo de que realmente son ellos los asesinos.

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.

Cuando un amigo de Hoppy muere al intentar huir de la cárcel, le echan la culpa a él y le expulsan de los Texas Rangers.

La llegada de la ingenua maestra June Lake al villorrio donde el caballeroso Hopalong Cassidy tiene su famoso rancho Bar 20, revoluciona la vida de los vaqueros. Pero también irrumpe por allí el cuatrero Sutton, quien con sus forajidos aterroriza a los pueblerinos y roba el ganado del rancho

Buck Peters arranges for Hoppy, California, Johnny and other cowboys to go to the aid of friends whose cattle are being rustled. Hoppy and California locate the rustlers' hideout and join the gang by posing as outlaws themselves, but must find a way to let the rest of the posse know where they are.

Hoppy is busy chasing stagecoach bandits who sing as they rob.

Posing as a cattle buyer, Hoppy crosses over into Oklahoma where the Jordan brother's and their outlaw gang operate outside the law. After receiving an unfriendly reception when he finds them, he, California, and Johnny rustle their cattle and drive across the river into Texas. He hopes they will cross over to retrieve their cattle and then he can arrest them.

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

Hoppy, California and Johnny come to the ranch of a friend and his daughter, disguised as dude detectives from the east, to investigate the disappearances, without a trace, of several herds of cattle.