Potash is a product used in fertilizer. It is high in potassium and is found naturally in underground deposits. It is a soft mineral, like salt. The Holbrook basin has been explored for oil and gas for a long time, without success. During those explorations, however, other minerals have been found, including potash in the 1960’s.
It wasn’t until the global price of potash, however, reached an historic peak in 2008 that this became news worth acting on. The Arizona Geological Survey issued a newsletter that year proclaiming “Arizona Has Potash” which began a small rush for mineral rights in the area of Petrified Forest National Park. The center of the estimated potash deposit is directly under the south end of the park.
Three companies emerged—one primarily east of the park named American West Potash, a second company with holdings primarily west of the park named Passport Potash, and a third privately held company named HNZ Potash centered around the NZ Milky Ranch, on the park’s southeast boundary.
Minerals directly under the park are federally owned and unavailable for mining. Minerals outside park ownership are either privately held or held by the State of Arizona and available for mining.
The two publicly held companies drilled into the potash to determine its composition, depth, thickness, and any other attributes they could gather in order to develop feasibility studies for mining operations.
Potash is between 800 and 1400 feet below the surface in relatively thin lenses of up to 30’ thick. The feasibility studies were made publicly available for shareholders and were used to seek investors. Each company proposed to build a mine of over $1 billion in initial cost and mine the potash for at least 50 years.
In 2013, a partnership halfway around the world from the Holbrook Basin dissolved and caused the global price of potash to tumble. From a high of over $800 per ton in 2009, potash now sells for just over $300 per ton and nearly all investment interest has evaporated. However, the minerals remain a known quantity and, should economic conditions for potash mining improve, mines could be developed someday.