McCormick received his law degree from Baylor in 1950. During the Korean War, he served in the Judge Advocate General's Corps. After the war, he became a city attorney in Midland, Texas. He later established a private law practice and entered the oil business. He served as president of Santiago Oil and Gas, Santana Petroleum Company, and Gold Metal Consolidation Mining Company. In 1958, he purchased a 320,000-acre ranch that later became Big Bend Ranch State Park. He died in 2012 at age 89 in Eldorado, Texas.
