A Texas Ranger turns bad and murders his partner for gold and greed and is hunted down by the son of the man he killed.
Lee Preston, aka Leland Bruce, kills a man in self defense but flees to the redwood country when the law makes it a murder charge. There he meets Lynn O'Malley, the niece of Sandy McTavish who runs the trading post. Lee learns the reason why this is good trapping country is because the timber barons across the lake are ruthlessly cutting the trees and driving the animals across the river. The trappers appeal to him to take a petition to the Governor which would prohibit the timber people from coming to their side of the lake. At first, because he is a wanted man, he refuses but does so later for the sake of the people even though he knows it will lead to his arrest.
Rodeo star Roy Rogers returns home to find that his old friend Tom Craig has been murdered after he was accused of stealing a family crest from Helen Williams (Evans). Helen joins up with Roy and Gabby Whittaker (Hayes) to find the killers and the crest. Arthur Courtney and his gang are behind the murder. Roy and Gabby find the crest hidden at the Craig ranch, but are quickly captured by the outlaws. Helen gathers together the Sons of the Pioneers, and Roy's local Indian friends to come to Roy and Gabby's rescue. An exciting film filled with action.
To get the Delaney ranch Cole's henchman Anders has started a phony range war between the cattlemen and sheepmen. After killing Delaney, he tries to kill his daughter Jill and then Roy who was sent to investigate the war. But the failed attempts gives Roy the information he needs.
Sintown is just a deserted ghost town until Vanerpool starts looking for silver. Cookie and Roy's partners put $20,000 into the business only to find that the mine is worthless and Vanerpool is bankrupt. Carol comes out to look for silver to save the company, but does not know that their engineer, named Regan, is crooked and wants all the silver for himself. But only Old Ed knows where the mother lode is located.
Horse breeders Adams and Brock are vying for the Army contract. When Adams is killed trying to ride his horse Trigger, Roy saves the horse from being shot. He trains him and then plans to ride him in the race to win the contract.
Bad guys plot to trick a newly arrived Eastern girl out of a ranch which belongs to her infant ward. Roy, of course, saves the ranch for the girl. Songs include "I'm Headin's for the Home Corral," "He's a No Good Son of a Gun," "Sandman Lullaby," "Song of the San Joaquin," and "I'm a Cowboy Rockefeller."
In this Roy Rogers entry, featuring a song written by Oklahoma Governor Roy J. Turner (making him and Lousiania's Jimmie Davis and Texas' W.E. "Pappy" O'Daniel possibly the only state governors to write songs used in a western), Flying U ranch owner Sam Talbot is killed by a fall from a horse. St. Louis reporter Connie Edwards comes to check a rumor that he might have been murdered. She goes to Roy Rogers, editor of the local newspaper, and he takes her to the reading of Talbot's will. The ranch is left to Talbot's 12-year-old ward, Duke Lowery, much to the dismay of Talbot's niece, Jan Holloway. After some attempts on Duke's life, Roy finally proves that Jan, Steve McClory and coroner Jim Judnick had Talbot killed and are conspiring to do the same for Duke, making Jan the last heir.
Cattle rustler Nevada dreams of living like an emperor in the West. Hoppy and the Bar 20 boys aim to put an end to his dream.
Hoppy goes undercover as an outlaw (which permits him, for once, to drink and be mean to children) to track down a bunch of outlaws operating along the border. Loco, the head bad guy, deflects suspicion from himself by pretending to be a moron.
Problems come in the form of one of Hopalong Cassidy's neighbors, but the matter is settled when Hoppy roots out the troublemaker.
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.
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. Hoppy and Bar 20 guys ultimately capture the professor.
Disguising himself as a milquetoast Easterner who writes Western novels, Hoppy enrolls in a dude ranch in order to unmask the murderer of the owner's husband.
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.
Hoppy and Lucky are headed to South America to deliver a heard of cattle. Bay guy Ralph Merritt gets in their way. For a while.
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.
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.
When the outlaw El Toro saves Hoppy's life, Hoppy agrees to find his missing grandson.