Semmes Foundation

Semmes Foundation

D.R. Semmes, an independent geologist, established the Semmes Foundation in 1952 to funnel his oil and gas proceeds into San Antonio's charitable, scientific, and educational causes. Today his son, Thomas R. Semmes, runs the institution as president, with his wife Patricia serving as vice president and secretary. While grants to local nonprofits — notably Trinity University, where Thomas is a former trustee and board chair — remain its visible face, the foundation quietly operates an endowment program that spans venture capital, buyouts, and secondaries. The investment strategy blends legacy mineral interests and Texas real estate with a modern multi-stage private equity program. The foundation pursues seed and early-stage venture deals, expansion and late-stage growth rounds, and secondary transactions. Public sources show it holds government obligations alongside its San Antonio commercial property at 800 Navarro Street. Operating with a lean family structure, the foundation lists no dedicated investment staff beyond the Semmes family officers. Its small professional footprint relies on the family's historical ties in San Antonio's business and social circles. An affiliation with The Argyle, a private club linked to the Texas Biomedical Research Institute, points to a sourcing model built on local, long-standing relationships rather than wide-open institutional solicitation. What distinguishes the Semmes Foundation is its dual posture: a conventional grantmaking body for San Antonio nonprofits that simultaneously runs a full private equity program more typical of a family office. This hybrid architecture pairs philanthropic distribution requirements with direct venture and buyout commitments, creating an investment engine fueled by the same oil-derived corpus that delivers charitable dollars.