406 Energy Holdings, LLC Announces Partnership with NGP

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HOUSTON--(BUSINESS WIRE)--Oct 10, 2025--

406 Energy, LLC (“406”) is proud to announce its formation with an initial equity commitment from NGP Natural Resources XIII, L.P. and the 406 Energy management team.

406 Energy was founded by four partners: Mark Graeve, Tom Kastens, Josh Sigler, and Eric Matus. The 406 management team has a history of working together, most notably as members of the pre-asset team at XCL Resources: an upstream oil and gas company that grew production to become the largest oil producer in Utah. 406 plans to focus on developing upstream oil and gas opportunities.

Patrick McWilliams, Partner at NGP, commented, “NGP is excited to partner with 406 Energy. The founders bring a combination of leading-edge reservoir characterization and data analytics, which, when combined, provide differentiated insights that are highly investable. The technical and operating capabilities at 406 are only surpassed by the team's character and winning culture. We look forward to supporting the 406 team as they build a durable, high-return upstream platform.”

Mark Graeve commented, “We are proud to partner with NGP to build an upstream business aligned with a common vision. We are grateful to NGP for this opportunity and all our former colleagues and field personnel whose hard work advanced the industry leading teams we have been part of.”

About 406 Energy

406 Energy was founded by technical leaders who bring expertise in identifying and developing high-return oil and gas assets. 406’s mission is to deliver strong production growth, operational efficiency, and long-term value. The standard behind the 406 name comes from Ted Williams, who in 1941 refused to sit out the final day of the season to preserve his .400 batting average, insisting, “If I’m going to be a .400 hitter, I want more than my toenails on the line.” Williams batted 6 for 8 and finished the season with a .406 batting average. That same spirit of commitment, confidence, and pursuit of excellence defines 406 Energy’s identity. For more information, visit www.406energy.com

About NGP

NGP is a premier private equity firm that believes energy is essential to progress. Founded in 1988, NGP is moving energy forward by investing in innovation and empowering energy entrepreneurs in natural resources and the energy transition. With $25 billion in cumulative equity commitments, NGP backs portfolio companies focused on responsibly solving and securing the energy needs of today and leading the way to a cleaner, more reliable, and more affordable energy future. For more information, visit www.ngpenergy.com

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CONTACT: Mark Graeve

Tel: 972.432.1440

KEYWORD: UNITED STATES NORTH AMERICA TEXAS

INDUSTRY KEYWORD: ENERGY PROFESSIONAL SERVICES OIL/GAS FINANCE

SOURCE: NGP

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PUB: 10/10/2025 09:00 AM/DISC: 10/10/2025 09:02 AM

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