Range Law stars Johnny Mack Brown as "Nevada" and Raymond Hatton as "Sandy", the same characters they played in most of their mid-1940s Monogram westerns. This time, Nevada and Sandy, US marshals both, set out to collar some renegades who've been driving out the local ranchers. It's just possible that one of said ranchers is behind this land-grabbing scheme.

Dan Stanton and Condon are foreclosing on a group of ranchers in order to gain a land-monopoly. They have one of the ranchers, whose property supplies the others with water, killed. Ann Jennings, niece of the rancher, sends for U. S. Marshals Nevada Jack McKenzie and Sandy Hopkins, who organize the ranchers who take over the dead man's property and blast the dam releasing needed water to all the ranchers. Nevada and Sandy, aided by the sheriff, round up Stanton, Condon and their gang members.

Brown's principal antagonist this time is the town boss, an outlaw who has killed the community's leading citizen. The dead man's grown children want to investigate the killing, but the outlaw puts a stop to this by hiring a dance-hall dame to pose as the kids' long-lost mother. Johnny isn't fooled by this subterfuge nor is his sidekick.

After escaping from jail, outlaw Wes McQueen is convinced by his old partner in crime to do one last heist.

J.D. Cahill is the toughest U.S. Marshal they've got, just the sound of his name makes bad guys stop in their tracks, so when his two young boy's want to get his attention they decide to rob a bank. They end up getting more than they bargained for.

Stodge City is in the grip of the Rumpo Kid and his gang. Mistaken identity again takes a hand as a 'sanitary engineer' named Marshal P. Knutt is mistaken for a law marshal. Being the conscientious sort, Marshal tries to help the town get rid of Rumpo, and a showdown is inevitable. Marshal has two aids—revenge-seeking Annie Oakley and his sanitary expertise.

A US marshal goes undercover to bust up a bunch of rustlers.

Lawman Wyatt Earp and outlaw Doc Holliday form an unlikely alliance which culminates in their participation in the legendary Gunfight at the O.K. Corral.

John Clark (Bob Steele) and his deaf pal, Bootch Collum (Buck Connors), are trailed by U. S. Marshal Lamar Bly (Jack Rockwell)...

At the height of the frontier era, a train races through the Rocky Mountains on a classified mission to a remote army post. But one by one the passengers are being murdered, and their only hope is the mysterious John Deakin, who's being transported to face trial for murder.

Taylor's men are robbing incoming supply wagons to enable Taylor to sell goods at inflated prices. The Vigilantes led by Frank Jackson are doing the same so the ranchers won't starve. Marshals Lash and Fuzzy arrive to try and find the real culprits.

A prospector discovers natural cement and suggests it should be used for a new dam. But this is the last thing the badmen of Trail End want, as they have a monopoly of the wagons needed to haul rocks to the site. A pretty sheriff notwithstanding, it's a job for a singing marshal.