Mariana Minerals said on August 3 that it raised $310 million in a Series B financing led by Khosla Ventures, hitting an implied $1.5 billion valuation and pushing total capital raised past $400 million as the AI-driven mining startup accelerates its build-out of U.S. copper and lithium production.
Khosla leads with a16z and Breakthrough back in
Founder Vinod Khosla wrote the lead check through Khosla Ventures. Andreessen Horowitz and Breakthrough Energy Ventures re-upped, while Greenoaks, Halo Fund, Pax Ventures, StepStone Group, BHP Ventures, Washington Harbour Partners, Greycroft, General Innovation Capital Partners, Mitsubishi Corporation, In-Q-Tel and Earthshot Ventures joined new. "The minerals are there. What has been missing is the will and the AI to run mining and refining autonomously," Khosla said in the announcement.
Copper One and Lithium One anchor the roadmap
The proceeds fund Mariana's active project portfolio, led by Copper One in southeastern Utah and Lithium One in East Texas. Copper One, acquired in late 2025, restarted mining operations under autonomous orchestration within four months and is ramping toward a 50,000-metric-ton-per-year refined copper target. Lithium One, which broke ground in Q4 2025, is being built as the world's first gigawatt-hour-scale facility for extracting lithium from oil-and-gas produced water, with commercial output slated for the first half of 2027. The playbook has already put Boston Dynamics Spot units on the Copper One rock face.
MarianaOS: one AI stack for CapEx, plant and mine
Mariana engineers, builds and operates mines and refineries on its proprietary MarianaOS platform, which stitches together CapitalProjectOS for capital project execution, PlantOS for refinery operations and MineOS for mine management inside a single AI and machine-learning stack. The company said MarianaOS compresses traditional 5-to-10-year project execution timelines by roughly half and drives commissioning well below industry benchmarks.
10-in-10 plan to reshore critical minerals
CEO Turner Caldwell framed the raise as a scaling round, saying Mariana has spent two years proving the software model and now plans to develop 10 commercial-scale projects in 10 years to strengthen domestic supply of the critical minerals feeding batteries, defense electronics and grid infrastructure. Every project generates operational data that improves MarianaOS, reducing the cost and time to build the next one. The strategy dovetails with rising U.S. policy support for domestic minerals following recent Pentagon Office of Strategic Capital commitments to reshore defense-critical supply chains.
Reporting based on coverage from PR Newswire, MINING.COM, TheAIInsider and Cooley.