The founder of the small Colorado town of Beckton asks his friend, Steve Drake, for help, but is murdered by Stanton, the leader of a marauding band of vigilantes who profess to be on the side of law and order, before Steve reaches town. Stanton then contrives to have Julia Beck, the murdered man's daughter, elected as Beckton's mayor. Under Stanton's guidance, Julia, who does not know Stanton is responsible for her father's murder, then forms a citizens' government league, which prohibits everyone from using guns except the league's officers, who are all Stanton's men. After the mysterious masked avenger The Durango Kid is blamed for Beck's murder, Stanton sends for a hired killer named The Texas Dynamo to catch him. Unknown to Stanton and the others, Steve is the real Durango Kid. When Steve discovers the gunman dying of a snake bite, he assumes his identity. As The Texas Dynamo, Steve takes over the vigilantes. Then Julia's brother Bill is framed by the vigilantes for a bank robbery. Aided by Smiley Burnette, Steve, disguised as The Durango Kid, reveals the real nature of the vigilantes and forces Stanton to confess that he murdered Julia's father.