Milane Frantz

Milane Duncan Frantz's father, Dan Duncan, founded Houston-based pipeline giant Enterprise Products Partners in 1968 and took it public in 1998.

Frantz and her three siblings inherited a stake in the company after their dad died in 2010; only Randa Duncan Williams is involved in the business.

Enterprise Products Partners now owns around 50,000 miles of oil pipelines and the largest oil storage facility on the Gulf Coast.

A board member of Houston's Hermann Park Conservancy, Frantz also serves as a director of the Duncan Family Foundation.