Houston Simmons, CFO at Black Mountain, is today’s Forty Under 40 featured honoree.

Houston was the third hire by investment banker Bobby Tudor, who was then working to expand his startup platform that went on to become Tudor, Pickering, Holt & Co. (TPH).

He had started his career at Credit Suisse’s global energy group, where he worked as an investment banking analyst before joining TPH in 2007 to help build the business from the ground up.

“Our first office space was Bobby Tudor’s pool house,” Houston said. “It took a lot of time and effort to build the franchise; I am proud of my contributions to TPH’s early years and I have enjoyed watching its continued success.”

Still, Houston said some of his greatest achievements—and challenges—unfolded after joining Black Mountain in 2016. Specifically, he counts the $700 million sale of Black Mountain Oil & Gas to Marathon Oil Corp., which he oversaw, to be a career highlight.

Click here for Houston’s complete profile.

Take a look at all of the Forty Under 40 honorees.