The U.S. Forest Service (USFS) has signed South32 Hermosa’s Final Mine Plan of Operation (MPO) during a ceremony at the project site in southern Arizona, authorizing South32 to conduct operations on U.S. Forest Service land.
The news follows the U.S. Forest Service’s issuance of the Final Record of Decision on July 7th which found the project has the smallest disturbance footprint and minimizes effects on environmental resources.
This establishes the federal framework under which South32 can develop and operate ancillary infrastructure on U.S. Forest Service land needed for Hermosa’s full development beyond its privately held land, including the Primary Access Road, secondary drystack tailings storage facility, and other supporting operations.
Arizona had already permitted the mine itself, allowing construction on private land to reach roughly the halfway mark. Federal approval covered infrastructure crossing public land, including a high-voltage transmission line, a second access road, tailings storage and water discharge points.
Hermosa hosts one of the world’s largest undeveloped zinc deposits, a battery-grade manganese deposit and the emerging Peak copper discovery. Together, they could support a 70-year operation producing five federally designated critical minerals.
Construction is already half-way complete on private land with zinc mining underground expected in late 2027 and first zinc product from the processing plant in the first half of 2028, the company said.
Hermosa was the first mining project added to, covered under, and completed in the federal FAST-41 permitting program, a process reserved for infrastructure projects that must meet certain criteria to demonstrate how they will benefit the US as the critical minerals race accelerates.
South32 plans to begin initial earthworks activities and surveys to support exploration drilling and geotechnical investigations in the coming weeks, representing the first physical activity enabled by the federal approval.
“This is the moment when years of planning, environmental study, consultation and permitting turn into action,” South32 Hermosa president Pat Risner said in a statement. “I am thankful to our team, government partners as well as our lead agency, the Forest Service, who showed collective will and steadfast commitment to completing the permitting process with rigor and on time.”
“Having our Mine Plan of Operations signed means we can begin developing the infrastructure needed to complete Hermosa and deliver on our vision for a different kind of mine designed around advanced technology, sustainability, and lasting value for Southern Arizona communities.”
Senior federal officials joined South32 employees and local stakeholders at Hermosa Wednesday to recognize the milestone, including representatives from the Federal Permitting Improvement Steering Council, U.S. Department of Agriculture (USDA), U.S. Forest Service and U.S. Fish and Wildlife Service.
“USDA and the Forest Service are committed to permitting projects on businesses’ timelines, not government’s,” USDA Deputy Secretary Stephen Alexander Vaden said.
“Projects such as the Hermosa project advance our national security objectives by making our country less reliant on others for critical minerals.”
