It’s been seven years since Forrest Fenn announced the existence of the buried treasure, said to be worth nearly $2 million. It has prompted thousands to comb areas of New Mexico, Yellowstone National Park and elsewhere.

The design of metal detectors well-suited for prospecting is an interesting process and not necessarily an easy one to achieve. It is a combination that blends the desires of what prospectors would like, the requirements of sales people and dealers, with the science and physics of what the electronics can achieve.

Within this area, about two million ounces of gold and fifty million ounces of silver have been mined. Faults, dikes, veins and fissures that carry the ore form a concentric radial pattern—like spokes on a wagon wheel—around the caldera core.