Gauchos of El Dorado

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

It is 1853 and settlers are pouring into California which means trouble for the old Spanish landowners. The El Dorado Mine Co. wants the land of Don Ortega for the minerals and is using the settlers and his friend Don Carlos to take the land over. But Tucson is on the side of Roberto and see's that something is not right with all the trouble they have been having. But the situation turns ugly for Don Ortega when Roberto is set up for a murder he did not commit.

After a payroll robbery the Mesquiteers catch up with the gang. But the members escape, the gang leader is killed, and they end up with only the leaders young son who is quickly sent to a work farm. They adopt the boy hoping to learn where the money is. Just as their kindness is about to pay off a gang member takes the boy away forcing him to retrieve the money. - Written by Maurice VanAuken

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

David Ross organizes the ranchers into a vigilante group to rid the town of outlaws. The plan succeeds but the trouble starts when some of the men form a new vigilante group and posing as the original one plunder for loot.

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

Stony's brother George has been accused of murder and the Mesquiteers have returned to prove his innocence. But they find that Harvey rules the town along with his stooge Sheriff Gray and that George won't get a fair trial.

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 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 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.