Donald Trump's pick for Energy secretary, Rick Perry, sits on the board of directors of Energy Transfer Partners, the company whose Dakota Access Pipeline has been fiercely opposed by Native American tribes and their allies.

Dallas-based Energy Transfer's top executive and other employees also contributed millions of dollars to support the former Texas governor's short-lived 2015 bid for the White House.

Perry joined the board of Energy Transfer Partners in February 2015 after serving as Texas governor for 14 years. Energy Transfer Partners said it selected him "because of his vast experience as an executive in the highest office of state government" and his familiarity with "finance and budget planning processes throughout his career."

Energy Transfer Partners Chairman and CEO Kelcy Warren donated $5 million to Opportunity and Freedom, a political action committee that backed Perry's candidacy, according to a Federal Election Commission filing. The PAC reimbursed Warren for $3.99 million of that amount in September 2015, shortly after Perry dropped out of the race, records show.

For the 2016 election, Energy Transfer Partners employees donated a total of $1,518,500 to Perry's campaign and outside groups supporting him, according to a list compiled by Open Secrets.