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.