U.S. District Judge Larry Hicks in Reno, NV has vacated the U.S. Bureau of Land Management’s approval of Eureka Moly’s planned molybdenum mine about 250 miles east of Reno. The ruling is in effect a stricter interpretation of a century-and-a-half old mining law that blocks a metals mine in Nevada.

According to the Associated Press, the ruling could have ramifications for the Thacker Pass lithium mine near the Nevada-Oregon line and other future mines on public lands across the West.

Hicks cited the 9th Circuit’s unprecedented ruling in an Arizona case last year regarding the Rosemont copper project that upended the government’s long-held position that the 1872 Mining Law conveys the same rights established through a valid mining claim to adjacent land for the disposal of tailings and other waste.

That ruling blocked construction of the Rosemont project based on the conclusion those rights don’t automatically apply to the neighboring national forest lands where the company planned to dump the waste rock. 

The company must instead establish that valuable minerals are present in such lands for a claim to exist, and the government will need to validate those results.

“BLM cannot skirt the Mining Law requirement that valuable mineral deposits must be found in order to occupy the land,” Hicks wrote March 31.

The AP reported that U.S. Judge Miranda Du in Reno cited the 9th Circuit ruling in concluding last month that BLM acted illegally when it approved Lithium Americas’ Thacker Pass mine near the Nevada-Oregon line. Du stopped short of vacating BLM’s approval of the project.

Instead, she moved the project back to the agency to determine whether there is sufficient evidence of valuable minerals to establish valid claims. Meanwhile, construction efforts are underway.

Eureka Moly LLC (EML) argued it did not intend to permanently occupy the adjacent lands because the mining at Mount Hope would end in 40 years.

However, in the decision Hicks said, “Although EML’s authorization to use the land will expire when the project is complete, the waste rock will remain. Thus, EML’s occupation ... will be permanent.” The “Rosemont (decision) requires that to permanently occupy the land as EML proposes, valuable deposits of minerals must exist.”

“The Mount Hope case did not impact Thacker Pass,” said Tim Crowley, Lithium Americas. “The Thacker Pass and Mount Hope cases addressed different facts, different legal arguments and had different outcomes,” he wrote in an email to The Associated Press. “The judge in our case thoroughly considered the specific Thacker Pass details in rendering her decision, and the project is now in construction and moving forward.”

Image of molybdenum courtesy of Shutterstock.