When Professor Marsh disappears while searching for the lost city of Lukachukai, his daughter enlists the help of the Three Mesquiteers.

Commissioner Tredwell is the law of the land and he gets whatever he wants with the help of hired guns and lackey lawyer Conners. The only one who publicly stands up to Tredwell is Beecham of the Clarion. Beecham has his paper burned to the ground and when he starts a petition to make Wyoming a state, taking the power away from Tredwell, he is killed. But when Kansas Kate comes in to visit her son Conners, she sees what is going on and she takes over the paper and keeps the pressure on Tredwill. With this Conners has mixed emotions, but the boys do everything they can to protect Kate and the paper. Written by Tony Fontana

Stony Brooke, Rusty Joslin and Rico, known as The Three Mesquiteers, return to Oklahoma at the close of the Spanish-American War, and are concerned that some of their wounded buddies have no prospects for a satisfactory future. When the government offers preferred homesteads in the newly-opened Oklahoma territory to war veterans, they send word for their pals to join them there. Once there, the veterans meet a hostile reception as the cattlemen resent the influx of "nesters" and are determined to drive them out. Mace Liscomb and his brother Orv plan not only to drive out the homesteaders, but to also double cross the cattlemen and gain exclusive titles to the range lands for themselves. Stony and his pals eventually show the honest cattlemen that there is room for the settlers and that both are fighting a common enemy. Written by Les Adams

It's "The Three Mesquiteers" again. Gaucho escapes from Braden's gang only to be shot by them. The Mesquiteers drive away the outlaws and take his money on to his mother. But Isabella thinks Tucson is her long lost son and they don't have the heart to tell her he is dead.

The Cherokee Strip is off limits to the Rangers, so that is where badman Lemar operates from. When the Rangers capture his brother and the jury sentences him to hang, Lemar starts killing the jurists. Then the scoundrels kidnap the Captain's daughter Doris... Written by Tony Fontana

A crooked real estate manipulator sells worthless land on mortgage to flood refugees, then tries to profit by reselling the land to the state, committing murder in the process, as the Three Mesquiteers work to bring him and his gang to justice.

The Mesquiteers capture a horse thief who escapes justice through a crooked judge. They gather signatures urging the governor to investigate but a friend with the petition is murdered. Stony is accused.

The Three Mesquiteers, as army scouts, soothe hostilities between the Army and Indians after both have been riled by someone with a hidden agenda - a renegade chief, who is found to be masquerading as an Army interpreter.

The Mesquiteers try to help their friend build a telegraph system, despite a local newspaper editor's attempts to sabotage the lines.

A banker struggles to keep his bank solvent and his town from going bankrupt after the bank is robbed and all its money taken. The Three Mesquiteers ride into town and set out to help.

The Three Mesquiteers convince a group of settlers to exchange their present property for some which, unbeknownst to our goodguys, is going to be worthless. They are captured before they can warn the ranchers.

After gold shipments from a mining town have been hijacked, the three Mesquiteers buy a plane to fly the gold out. The owner of the shipping line brings in Eastern gangsters to thwart them.