Tim Spencer

To bring water to their valley, ranchers have raised money to build a dam. When that money is stolen, Allison suggests the ranchers sell their stock to a friend of his thereby getting the money needed to complete the dam. Roy has a clue that Allison was involved in the robbery and is out to get control of the valley. So Roy and the boys try to delay the sale of the stock while they look for proof against Allison.

Roy is a government man assigned to a case of cattle rustling in the part of the country where he grew up, unaware that the leader of the gang is a woman, in fact an old flame.

Jerry Johnson inherits a 50,000 acre ranch. Lucky Miller wants to take over the ranch. Roy is trying to get a railroad spur right of way. Lucky has a woman come west to marry Jerry to get control of the ranch. After the wedding, Lucky has the owner killed. Roy’s gun is substituted for the murder weapon, so Roy is put in jail.

A deputy sets out to prove that a respected judge, who had once been a criminal, is being framed for crimes committed by a crooked saloon owner.

A singing entomologist (Roy Rogers) acts meek to help a juggling sheriff (George "Gabby" Hayes) solve ranch raids.

Unable to pay her notes, Ann Bradford, owner of the Circle C, decides to auction off a half-interest in her ranch. Matt Stark, a crooked land dealer, holds Ann's notes. His efforts to buy the ranch have been refused and his instructs his henchman, Barlow, and his other henchmen to make certain that nobody bids on the ranch. Clint Buckley rides into town on the day of the auction, overhears Stark's instructions to his henchies, and decides to attend the sale. Barlow attempts to intimidate him, they fight, Buckley wins and his bid of $25,000 wins him a half-interest in the Circle C. But, Stark, isn't finished yet in his efforts to get the ranch, especially since a couple of his hirelings are on the Circle C payroll.

Cowboy Jeff Larabee returns from the east and meets Doris Halloway, a young girl, that he regards as a vagabond, till he learns that she's the owner of the farm where he works. He tries to win her heart, but without success, until she is endangered by gangsters

Fur theives are looting the traps on the ranch where Roy is foreman and they have murdered one of Roy's friends.

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."

Roy Rogers, Smiley Burnette and the Sons of the Pioneers go undercover to help Texas Governor Russell Hicks stop World War II Axis sympathizers from blowing up U.S. warehouses.

A radio saleswoman helps a singing cattleman trap a shady meat buyer with a bogus broadcast.

Roy returns home to fine a range feud between the cattlemen and the sheepmen. When his friend is killed he finds the rifle had a defective pin. He learns the rifle belongs to a ranch hand named Barker and that a third party has caused the feud. When he captures outlaws trying to blow up a dam, he claims Barker was the killer. But Barker has switched rifles and the outlaws now accuse Roy and Roy finds himself in trouble.

Steve Beaumont, an operative for the Cattleman's Protective Association, is assigned the difficult task of breaking up a murderous gang of rustlers led by Ed Brock and Strang. He takes Sheriff Webb, Judge Baxter, and rancher Ann Houston into his confidence, and works his way into the rustler stronghold and confidence by "turning rustler" himself.

Frank Sr. sells his supplies to Hook, but then Hook has the Bannion Boys bushwhack his wagon to get the money back. Frank is murdered, but Junior gets away. He comes back 10 years later to settle the score as the Singing Cowboy. He finds that Hook is still doing his dirty deeds on the unsuspecting people. Along the way, Frank meets the lovely Jen, who came out in the same wagon train 10 years before.

To get the three needed business men to visit the Stevens mine, Roy stages a ride with the Vacaros and has them as honored guests. Seeing a chance to make a lot of money, gangster Harmon joins the ride and then has his men kidnap the three. Having filmed a fake holdup earlier, he uses the film to convince the Sheriff that Roy and the boys were the Kidnapers.

A man of no worth brags to his daughter back East that he is rich and owns a big ranch. When she decides to pay a visit to her father, Roy and his buddies agree to pretend that the poor man is the owner of the ranch.

The Pony Express is finished as the Post Office plans to award the mail contract to a stage line. Bill and his father put in a bid for the mail, however there are three bids close together. The officials will run a race to pick the winner, and the Banton Brothers sabotage Bill's stage. Mary still believes in Bill until they try to get rid of him by holding up the regular stage with his well-known horse. Bill needs proof to clear himself and expose the bad guys.

Judge Kirby is being blackmailed and forced to let outlaws go free. He was once the partner of Roy's father and when Roy reads in the paper that he is in trouble he heads out to help him. Arriving, Roy quickly realizes he has been mistaken for one of the outlaws and is not wanted in town. However he stays, and now posing as that outlaw, hopes to learn who is causing all the problems.

Roy is an oil prospector. His efforts to get drilling rights on an old Spanish land grant are countered by gamblers from an off-shore gambling boat determined to control the land (and oil) themselves.

A New York radio talent scout turns up at a barn dance.

Lambert owns the trucking line that ships cattle to market. When he raises his rates Roy decides to ship the cattle on the River Boat. When Lambert and his men are unable to stop the boat, they rustle the cattle.

Thelma and Patsy get jobs at a radio station.

Roy Rogers takes on crooked wartime profiteers in the musical western Ridin' Down the Canyon. Posing as solid citizens, the crooks spend their evening hours stealing horses from local ranchers, then selling the steeds to the government at exorbitant prices. The head of the bad guys runs a dude ranch where Rogers and his pals (The Sons of the Pioneers) are employed.

After a handful of non-formula westerns, Charles Starrett returned to the mixture as before in Thundering Frontier. Starrett plays Jim Fillmore, kind to old ladies, small animals and heroine Norma Belknap (Iris Meredith). In contrast, the villains are kind to no one, least of all struggling building contractor Square Deal Scottie (Alex Callam), whose projects are continually targeted for demolition and his payroll is forever being stolen at gunpoint. A good 25 percent of the film's running time is given over to Bob Nolan and the Sons of the Pioneers, whose C&W croonings are pleasant but a bit much. One of the film's few surprises is that Starrett's perennial screen sparring partner Dick Curtis isn't one of the bad guys.