Yerington copper mine, Lyon County's largest underground site, to reopen

SEATTLE (Scrap Monster):  Plans are in the works to reopen the largest underground mine in Lyon County.

Southwest Critical Minerals, a subsidiary of Kinterra Capital Corp., of Toronto, has been working to reopen the shuttered Pumpkin Hollow copper mine seven miles southeast of Yerington. The mine has been closed since Nevada Copper Corp., filed for Chapter 11 bankruptcy protection in June 2024.

After acquiring the property in 2005, Nevada Copper fully permitted underground mining operations at Pumpkin Hollow and spent years constructing a mill, 400-ton headframe and a 24-foot concrete-lined main production shaft that plunged more than 2,000 feet below the surface. The underground mine was plagued by a host of geotechnical and financial problems, though, including unexpected underground flooding that hampered ore production and depressed copper prices that strained Nevada Copper’s balance sheet.

Kinterra Capital acquired the mine site and infrastructure in October 2024 for $128 million. Nevada Copper laid off 117 employees when it wound down operations, but the restart by Southwest Critical Minerals could provide a significant bump to employment in south Lyon County.

The 22,826-acre Pumpkin Hollow project has more than $1 billion in installed infrastructure, Kinterra reported. The underground mine contains an estimated 1.7 billion pounds of copper, but the potential at the large, fully permitted open pit mine is far greater, Kinterra said in a news release.

Last September, Kinterra announced it had secured $80 million in equity financing by privately held investment firm Lionhead to advance its work to restart the stalled mine.

“Kinterra's restart of Pumpkin Hollow and the advancement of the Southwest Open Pit are pivotal milestones for our large and growing U.S. copper portfolio and for U.S. copper supply chains,” Kinterra co-managing partner Cheryl Brandon said. “Within the next 24 months, we expect to have a producing and cash flow generating underground copper mine and a shovel-ready open pit, all in Nevada.”

Initial mining operations could produce approximately 228 million pounds of copper each year, or about 5-7 percent of current U.S. copper demand, Brandon added.

Paul Quirk, Cape Town-based co-founder and managing partner at Lionhead, said his firm’s operating experience in the mining industry and global networks will accelerate the delivery timeline of copper from Pumpkin Hollow once mining operations resume.

“Pumpkin Hollow is exactly the type of investment that Lionhead seeks to invest in: a high-quality asset with a clear path to restart and a management team with a proven ability to execute,” Quirk said.

Pumpkin Hollow’s underground restart is being led by mining industry veteran Ian McMullan, who helped start Newmont’s Leeville underground mine and also oversaw the expansion of the Carlin Portal mines on the Carlin Trend in northeastern Nevada.

In early November of last year, Kinterra Capital and Southwest Critical Materials secured a non-binding letter of interest from the Export-Import Bank of the United States to provide as much as $200 million in debt financing for its efforts to restart the Pumpkin Hollow mine. The official export credit agency of the federal government would potentially provide Kinterra with $180 million in to complete the restart of underground mining operations, along with an additional $20 million to advance technical work on the open pit mine.

“With EXIM's support, the restart of Pumpkin Hollow is now fully financed,” McMullan said in a statement. “The underground mine’s existing infrastructure allows us to efficiently bring the operation back online and contribute to strengthening secure, resilient supply chains for copper.”

Since acquiring the mine, Kinterra has started re-logging more than 37 miles of previously drilled core samples to update its resource model and gain clearer hydrogeologic understanding of the deposit. The mine team is also optimizing ore handling processes across the site from the mine face through the mill, parts of which are being refurbished.

Restart activities are also focused on creating a complete geological resource update that incorporates advanced core scanning for increased mineral identification and interpretation. Kinterra said it is also in discussions with potential downstream offtake partners.

South of the underground mining operations, Kinterra is working on a feasibility study for initiating open-pit mining operations. According to work completed by Nevada Copper, the open pit portion of the Pumpkin Hollow mine contains approximately 3.6 billion pounds of copper with an expected 20-year mine life.

The Toronto-based copper miner appointed Christopher Schauffele to oversee open pit operations. Schauffele oversaw both underground and open pit operations at the Candelaria Copper Mining Complex in Chile.

Courtesy: www.nevadaappeal.com