The hero, Texas Ranger Larry Whalen (Charles Starrett), is on the trail of a mysterious outlaw leader.

Sea Captain Windwagon Smith hits Westport, Kansas, the starting point of the old Oregon and Santa Fe Trails, and is quickly the laughing stock of the town; instead of traveling in the usual oxen-drawn covered wagon, he is at the helm and wheel of a Contestoga-type wagon with a full set of sails. He plans to go to Oregon by taking advantage of the prairie winds. First, he wins over the town mayor, falls in love with the mayor's beautiful daughter, Molly Crum, and then secures financial backing from the townspeople. He sets sail across the plains, with Molly Crum as a covered-wagon stowaway, and a Kansas twister looming on the horizon. And, then, the wind hits the sails. And the fan, too, if he had had one.

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.

Twenty years earlier Farrell killed his mining partner Andrews. Now Andrews daughter arrives to get her father's trust fund. Farrell having rustled Roy's cattle now takes her money from her Lawyer and lets her overhear false information of their next rustling job. With the posse at the wrong location, his men attack the cattle train and Roy on board find himself greatly outnumbered.

On vacation at his ranch, western actor Roy quickly finds himself involved with a horse rustling operation and a boy ward of one of the rustlers, leading to the kidnapping of Roy's trick horse Trigger by the gang with a demand for ransom.

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.

The Kinkaids and the Harpers both run stage lines and are friendly competitors. Appleby is after the stage line and convinces the two owners to build a spur line to the same town. Then he has both projects sabotaged pitting the friends against each other and running them out of money.

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.

Lt. Col. Kirby Yorke is posted on the Texas frontier to defend settlers against depredations of marauding Apaches. Col. Yorke is under considerable stress by a serious shortage of troops of his command. Tension is added when Yorke's son (whom he hasn't seen in fifteen years), Trooper Jeff Yorke, is one of 18 recruits sent to the regiment.

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

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

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.

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.

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.

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 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.

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.

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 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 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.

Story of how the Coast Guard trained to help win World War II.

The Marshal of Santa Fe returns home to find his town almost wiped out by Mexican bandits and enlists the help of a young Mexican boy and his mother to track them down.