Stalwart Supporter Named Life Trustee

Throughout its history, St. Mark’s Board of Trustees has reserved its highest honor – appointment as Life Trustee – for the School's most exceptional leaders. Names like Green, McDermott, Rogers, and Hoffman comprise the pantheon of these extraordinary luminaries in St. Mark’s history. 

At its annual Trustee Dinner on Monday, May 5, 2025, the Board bestowed this distinction upon one of its longest-serving members: Casey McManemin ’79. Casey’s time on the Board spans 30 years and includes service on multiple committees. Additionally, he helped advance the School's mission as a co-chair of The Centennial Challenge campaign. Together with co-chairs Kathy Crow and Wallace Hall ’80, Casey led the campaign to a successful conclusion in 2013, which raised over $112 million. In 2014, the Alumni Association honored Casey’s dedication with its highest distinction for service to St. Mark’s, the Alumni Service Medal.  

 

Former Trustee Wallace Hall introduced Casey at the Trustee Dinner, referring to his friend as “the quintessential Marksman.” 

 

“Casey has contributed meaningfully to shaping our School’s destiny and always behaves with a deep sense of loyalty to St. Mark’s and care for those around him,” Hall said. “He has unquestionably left St. Mark’s a far, far better institution than when he arrived and has enriched all the lives of those with whom he has served.” 

 

While Casey has demonstrated remarkable commitment in his service and support of the School, Eugene McDermott Headmaster David W. Dini noted how much of Casey’s dedication was in “the intangibles.”  

 

“I can think of many occasions where Casey has stepped forward quietly, behind the scenes, to intervene and lead on behalf of the School,” Dini said. “And he does so while asking for no fanfare. That’s just the kind of servant-leader he is.”   

 

Casey’s appointment was made official at a Board of Trustees meeting in January. Board President Fraser Marcus ’72 read a proclamation, which concludes:  

 

“It is the unanimous opinion of the Executive Committee, the Committee on Trustees, and the Board that Mr. McManemin has clearly exhibited lengthy, outstanding, and meritorious service as a trustee, which is indicative of a lifetime of extraordinary and substantive commitment to St Mark’s School of Texas and its programs, including important and institution-shaping contributions of time, energy, creativity, vision, and resources. Therefore, be it resolved the St. Mark’s Board of Trustees hereby approves this resolution and confirms the election of Mr. William Casey McManemin, Class of 1979, as Life Trustee.” 

 

After his father passed away when Casey was just ten years old, his mother was left to raise three boys. Casey’s teachers identified his potential and encouraged him to apply to St. Mark’s. With help from a scholarship, he enrolled in seventh grade. He quickly found himself embraced by a community that supported him and his entire family. After St. Mark’s, Casey studied petroleum engineering and successfully led Dorchester Minerals, LP as the longtime CEO. All the while, he never forgot the support that allowed him to attend St. Mark’s.

 

Throughout his decades of involvement, Casey has been a vocal supporter of Access & Affordability. In 2009, he joined with Bob Roberts ’64 to create the Alumni Financial Aid Challenge, helping raise over $10 million. In ways large and small, Casey has found ways to consistently and deeply engage with and support the lives of Marksmen. 

 

Casey McManemin is a Marksman, a leader, and an advocate — shaped by a remarkable community and dedicated to shaping it in return.