Bustling scenes show Edwardian Derry-Londonderry before industrialisation took hold.
Cattleman Flint cuts off farmer Sims' water supply. When Sims' son Ted goes for water, one of Flint's men kills him. Cheyenne is sent to finish off Sims, but finding the family at the newly dug grave, he changes sides.
On a ranch in Wyoming, one of the cowboys, Cheyenne Harry (Harry Carey), falls in love with his boss's daughter. But she decides to elope to the city with Captain Thornton, a wealthy visitor to the ranch. She quickly discovers that life in the city is not what she expected. Cheyenne, devastated by the loss of his fiancée, decides to go to the city to find her, and in the end rescues her from the grips of Captain Thornton and from the extravagant and decadent way of life in the city.
A farm girl learns she is a princess and is swept away by a tornado to the land of Oz.
A cowboy arrives to help a girl who has a note due. He plans to sell her cattle to raise the money but they are stampeded and most are killed. Knowing who stampeded them gives him another plan to get the money.
A young woman inherits her father's large Texas ranch and plans to begin a cattle drive to Abilene, Kansas, 1000 miles away. The crooked State Treasurer plans to attack the cattle drive and steal all of the stock so he can gain control of her ranch.
Seeing cattle dying of thirst, a stranger shoots a hole in Hoades water pipeline. Hoades is hoarding water trying to drive the ranchers away. Hounded by the law for stealing a pie, the stranger sees a chance to redeem himself by forcing Hoades to sell his pipeline and leave the area.
Bob Warner sells some cattle to two men who later drug him and rob him of the sale money. He takes a job with a medicine show as a barker, offering a reward to any spectator to last three rounds in fighting him. While in the ring, he notices in the audience the two men who stole his money. He knocks out his contestant, pursues the crooks, and recovers the money.
Jim Wyngate, an English aristocrat, comes to the American West under a cloud of suspicion for embezzlement actually committed by his cousin Lord Henry. In Wyoming, Wyngate runs afoul of cattle rustler Cash Hawkins by rescuing the Indian girl Naturich from Hawkins. Wyngate marries Naturich, but then learns that his cousin Lord Henry has been killed and has cleared his name before dying. As Wyngate has long loved Lady Diana, Lord Henry's wife, he is perplexed at his situation. But fate takes a hand and resolves matters as Wyngate could not have predicted.
Captain Porter's scheme is to buy livestock and then have his men show up later to kill the buyer and retrieve the money. When his men kill the next victim, he frames the Arizonian for the murder. The Arizonian escapes the law and joins up with the outlaw Vasquez. Knowing Porter's scheme, he plans to trap him by using Vasquez as the next buyer.
A noted gunman takes a job on a cattle ranch to stop a band of rustlers.
Karger is behind all the cattle rustling. After Tom Devlin catches his man Burke in the act, Burke hides evidence against Karger in his jail cell. Later when Tom is jailed he accidentally finds the evidence, but the Karger encited mob has jailed the Sheriff and is already on the loose.
Running from the law, Jim Hall joins Hays’ gang. Hays is foreman on the Herrick ranch and plans to rustle Herrick’s cattle. Attracted to Herrick’s sister Helen, Jim decides to tell the Sheriff about the raid. But when his plan is overheard he is made a prisoner.
A landslide has diverted water from the Baldwin ranch to Cambert's. With their cattle dying, Cambert refuses to let them have any water. Easterner Larry Knight takes a job with the Baldwins and he has a plan to divert the water back to the Baldwin ranch. But Phil, jealous of Kitty's attraction to Larry, lets Cambert know of the scheme.
Sunset of Power is regarded as one of Buck Jones' more meritorious Universal westerns. The heavy of the piece, grim-visaged cattle baron Neil Brannum, drives everyone around him mercilessly, including his own granddaughter Ruth. In retaliation, a caped-and-masked Spanish bandido stages nightly raids on Brannum's spread.
Mortimer builds a fence for the cattle brought by Ken Morley. To retaliate, Slater who wants access to the land, builds a dam cutting off Mortimer's water supply. When Ken confronts Slater, he is captured. Then lightning destroys the dam and Ken, imprisoned in a shack, is in the path of the oncoming water.
Ted Warren returns from WWI to find that everyone thinks he was dead. The culprit is Kent who intercepted his mail, rustled the Warren cattle, took over the Warren ranch, and is now after Ted's girl friend. When Kent's henchmen fail to kill Ted, Kent shoots Ted's father and leaves him for dead. But only wounded, the plan is to have Warren appear as a ghost to get a confession from Kent.
Someone is adding beef to Rocky Brown's herds and changing the brands to make it look like he is rustling. Then he is framed for murder and jailed. Johnny Argyle who has been sent to investigate believes he is innocent and sets out to prove it and starts with hides that have been rebranded.
A cowboy out to find out who murdered his brother discovers that the killers may not be who he thought they were.
The Transcontinental Broadcasting Company sends a sound truck and equipment to a ranch to obtain an audition from "Santa Fe" Evans and his musical cowboys (Oscar Gahan, Lloyd Perryman, Robert "Curley" Hoag, Rudy Sooter and Sherry Tansey.) Carver, arch enemy of Evans and a rival for the love of Carol Sheldon, fails in an attempt to spoil the audition. Carver frames Mr. Sheldon and Carol's brother Buddy on a charge, by Al Jensen, of receiving cattle stolen from him by Evans. Carver blames Evans for all of the Sheldon's troubles and, what with one thing or another, it looks like Evans and his cowhands will miss the big broadcast.