The character of Buckley is based on Adolph Ruth, whose knowledge of the Lost Dutchman came from his father through an employee of the Peralta family. He disappeared in the Superstition Mountains in 1931 and his skull was found half a year later with two bullet holes in it. Also discovered was his unfired pistol and his checkbook in which he had written that he had indeed located the mine. Over the years other murders and disappearances of treasure seekers have helped to build the legend.

The real Jacob Walz, who claimed that he had discovered the Dutchman, died of pneumonia after severe flooding on his Arizona ranch in 1891. He was nursed by Julia Thomas, the same name as the character portrayed by Ida Lupino in this film and reputed to have been a quadroon. She claimed Walz had told her the mine's location on his deathbed and even sold shares in a Lost Dutchman mining company, but nothing ever came of it.

The real Barry Storm, whose 1945 book had renewed interest in the Lost Dutchman Mine, did claim to have been shot at in the Superstition Mountains by a mysterious gunman known as Mr. X.

A furious Barry Storm sued Columbia Pictures, not only for plagiarism but also for "insidious Communist conspiracy." Storm was especially irate that the film had William Prince's Storm character as the grandson of Walz. The suit was ultimately settled out of court.

There were actually four different mines called the Lost Dutchman in American history. Two are in Arizona, one in Colorado, and one in California.

Continuity

When Julia joins the crowd following Walz to the assay office, she flips the sign on the bakery door from 'Open' to 'Closed'. However, when she returns, the 'Closed' sign is on the inside of the door again.

In the final fight between Deputy Ray and Storm, Ray can be seen wearing gloves in some shots and not in others.



Factual errors

Dutch repeatedly fires his revolver at the bar's swing doors, with people crowding behind them, not causing any injuries but only minor damage to the wood. In reality, some of them would have penetrated the wood and caused injuries.

When the little girl fires 'Jacob Walz' rifle there is no recoil. A rifle of that bore would have knocked her on her wallet.



Revealing mistakes

After killing all three at the site where the gold had been stashed, "Dutch" dumps all three bodies off the edge. Before the last body lands on the other two, the body on the left noticeably jerks.

When "Dutch" teases the little girl into firing his rifle, the rifle goes off before she pulls the trigger.

The rocks used by the Apaches to seal the mine are obviously fake.



Crew or equipment visible

In the scene where the Apaches attack the Spanish miners, one of the Apaches hurls a spear, hitting a miner. As the miner turns away and falls, you can briefly see light reflecting off of the guide-wire used to guide the prop spear to its target.