During his time as mayor in the late 1980s and early 1990s, he was instrumental in bringing the Colorado Rockies baseball team to Denver in 1993 .

[2] Although he had intended to leave Clinton's cabinet after a single term, Peña also served as secretary of energy from 1997 to 1998.

He developed the Clinton administration's Comprehensive National Energy Strategy and oversaw the largest privatization in the history of the U.S. Government—the $3.654 billion sale of the Elk Hills Oil Field, formerly known as Naval Petroleum Reserve No.

He crafted the Clinton Administration's strategy for oil and gas development in the Caspian Sea region and supported U.S. energy companies' investments around the world.

In August 1998, he joined private equity firm Vestar Capital Partners where he is a senior advisor.

The move was notable in that Peña did not endorse Senator Hillary Clinton, the wife of the president under whom he served.