The Dutchman himself was actually a German miner named Jacob Waltz. Born in Germany in 1808, he set out for America in 1839 looking to strike it rich. In 1848 he became a US citizen while in Mississippi. After not having much luck there, he decided to head west to California. He ended up in the Bradshaw Mountains, a mountain range in the Sonoran Desert in central Arizona, and was determined to find gold. In 1968, having made a homestead claim of 160 acres near the Salt River, Waltz would mine the nearby Superstition Mountains. For about 20 years he would head out every winter searching for gold. The story goes that on one of his excursion he found the notorious mine and left only a few clues on its whereabouts. In 1891, Waltz died in Phoenix and the mysterious location died with him.
As the famous story is told, these are the clues Waltz left on the mines location:
"From my mine you can see the military trail, but from the military trail you can not see my mine. The rays of the setting sun shine into the entrance of my mine. There is a trick in the trail to my mine. My mine is located in a north-trending canyon. There is a rock face on the trail to my mine."