Horowitz-backed firm to revive idled Utah copper mine

A startup backed by Silicon Valley venture firm Andreessen Horowitz plans to revive an idled copper mine in Utah to test new technology aimed at automating operations.

Mariana Minerals acquired the Centennial copper mine from Lisbon Valley Mining Co. LLC last year and will reopen it in April, according to Mariana’s chief executive officer Turner Caldwell.

The small mine produced about 2,500 tons of copper a year under Lisbon Valley’s ownership, though Mariana plans to scale the output to 50,000 tons of copper cathode by 2030. The firm will deploy autonomous equipment including haul trucks and drill rigs, Caldwell said.

“There just hasn’t been a lot of mining in the US in the last 50 years, partly because we don’t have the people to design and operate these assets,” said Caldwell, who spent about a decade at Tesla Inc. managing the automaker’s battery minerals unit before founding Mariana Minerals.

The reopening is the latest example of mining firms looking to revive idled US operations as metal prices climb and the Trump administration pushes to onshore critical minerals. BHP Group and Faraday Copper Corp. are exploring a deal to restart a historic copper mine in Arizona, while Blue Moon Metals Inc. acquired a defunct germanium and gallium mine in Utah from Teck Resources Ltd. in February.

The closely held firm was among several commodity companies that went to Venezuela last week as part of US Interior Secretary Doug Burgum’s visit to revive oil and mineral production in the South American country.

Mariana closed a Series A funding round in June 2025 backed by Andreessen Horowitz, Breakthrough Energy Ventures and Khosla Ventures.

(By Jacob Lorinc)