In Hillsboro, a long-silent copper mine may come back to life

HILLSBORO — The lonely block house sitting on a hillside beneath Animas Peak near the former Quintana copper mine in Sierra County does not look like a likely location for an imminent industrial boom.

Thirty miles from Truth or Consequences, the mine — which operated for about three months in 1982 before falling prices shuttered it — sits in a geological playground: A variety of volcanic rock and sediment from a Pleistocene lake bed display colors that shimmer on bluffs surrounding the stillness of the open pit. 

Piles of discarded rock combine with concrete, rebar and other construction debris. It doesn’t take long to find bits of ore twinkling in the sun with copper and other metal deposits.

Nineteenth-century discoveries of gold and silver in the Black Range made Hillsboro the center of a busy mining and ranching district and, for a time, the seat of Sierra County. The town once had its own copper smelter producing metal from porphyry deposits found amid the region’s granitic rock, which also holds gold and molybdenum, or “molly.”

Now known as the Copper Flat mine, the site has been the focus of a drawn-out permitting process and years of litigation as its owners — New Mexico Copper, a subsidiary of THEMAC Resources — aim to build a modern mining operation on this site and begin production in mid-2029.

For the moment, one employee at the location watches out for the occasional hiker, hunter or lone prospector. A rough-looking cat named Tito addresses any mice that get past the snakes and coyotes.

Senior Vice President Stephen Crosby, who joined the company a year ago, said in an interview during a recent a tour that the mine is preparing to begin major construction as soon as next year, pending permit approvals. Last September, the company submitted an amended operation and reclamation plan to New Mexico’s Energy, Minerals and Natural Resources Department that is pending. 

Over an operating life Crosby estimated at 18 years or more, the plan contemplates production of 145 million tons of ore and a yield of 628 million pounds of copper. The construction phase alone, requiring 18 months to two years, would employ up to 1,300 people, Crosby said. From the build to peak operations, he envisioned the mine becoming a major employer in the region, adding an industrial base to Sierra County’s economy. Crosby said his company has pledged to prioritize New Mexico workers.

“You have people here who have skill, and you have people who have will,” he said. “If you have the will to come up here and learn what we’re doing, we’ll get you the skill. But it doesn’t matter how much skill you have: If you don’t have the will, we can’t do anything for you.”

Modified operation plan

Copper Flat was forced to change its operating plans last year, moving to a less water-intensive production method. 

That followed a decision by the Office of the State Engineer rejecting a transfer of 2,400 acre-feet per year of groundwater rights from the Santa Teresa area, following objections from some neighboring ranches and the Percha-Animas Watershed Association, among other groups.

Prior to that, the mining company faced years of litigation over water rights and state copper rule requirements. Protests logged concerns about impacts to the area water table, crops and livestock, and potential infiltration from a future tailings pond into the Caballo reservoir.

Under the modified proposal, Copper Flat would use a dry-stack operation for its waste material instead of a wet tailing facility, reducing the groundwater needed from 6,100 acre-feet per year to 1,050 acre-feet.

While the “cake” deposits would still hold some water, Crosby said the technology would allow as much as 90% of its water to be recycled, and that the tailings would sit on doubled layers of lining material.

“No water leaves this site except through evaporation,” he said.

While the drier technology adds significantly to the cost of operations, Crosby said the market was secure enough to make the investment viable. 

Copper is a federally designated critical mineral and in high demand worldwide for consumer electronics, renewable energy infrastructure, a booming industry in data centers and much more. Inventories are low, global supply chains have been subject to disruptions and the U.S. sits on rich copper reserves, according to a recent outlook report by J.P. Morgan.

Crosby said the company was prepared to invest another $600 million on top of $100 million already invested into producing copper here and provide a needed economic boost to the region. Acknowledging critics, Crosby promised to build trust throughout the community.

“It scares people, and I get it. I don’t want to have my rivers polluted with anything, except maybe bait,” he said. “I can’t get stuff in the river. I can’t have people driving by here and seeing a big plume of dust. I don’t want to hear any noise. … We care just as much as everybody else.”

Public hearing requested

Some of the organizations that opposed the water transfer are skeptical that the mine has enough water left to carry out its plan.

The Gila Resources Information Project has requested a public hearing on the amended operation plan. GRIP’s executive director, Allyson Siwik, said the group’s technical consultants think the company is overestimating likely water savings and the mine would need considerably more than 1,050 acre-feet a year to operate.

Additionally, she said questions remain about air quality and the stability of stockpiled waste material.

“It just doesn’t seem like they were really serious about putting together a proposal that’s really going to work,” Siwik said.

Max Yeh, who leads the Percha Animas Watershed Alliance, said, “I don’t see what they can do with that mine. I’m pretty sure they don’t have enough water and they don’t have a bit of electricity right now. They have not struck a deal for an electrical contract with anybody, and their demand is huge.” 

Crosby said the mine was exploring building a solar array to meet some of the power demand at the site.

The $600 million in additional capital investment required before producing a single pound of ore — and given what Crosby reported is a two-year wait for power transformers needed to support mining — made the launch uncertain even with historic levels of demand, Yeh argued.

But Crosby said the company was serious about getting to work and contributing to the region’s economy.

“Mining is a process,” he said. “It’s a very proven science. As long as you follow the process, you don’t get anybody hurt, you’ll recover whatever you’re looking for and mining is a very boring job.”

For now, Tito and the long-quiet mine are waiting through the regulatory process.

Algernon D’Ammassa is the Journal’s southern New Mexico correspondent. He can be reached at adammassa@abqjournal.com.