D an Wilks, along with his younger brother Farris, is an American self-made billionaire who made his fortune in the hydraulic fracturing and oilfield services industry. The brothers, who are the sons of a bricklayer, started their careers as masons before identifying a major opportunity in the Texas shale oil boom. In 2002, they founded Frac Tech, a company that provided the high-pressure trucks and equipment essential for fracking.

They built Frac Tech from a small startup into one of the largest and most successful fracking service providers during the height of the U.S. shale revolution. In 2011, at the peak of the market, they sold their majority stake in the company to a consortium led by a Singaporean sovereign wealth fund for a massive $3.5 billion. The brothers have since used their immense wealth to become some of the largest private landowners in the United States, acquiring vast ranches in Texas, Montana, and other western states. They are also major donors to conservative and Christian causes.