Secretary of the Interior Ken Salazar announced he’d retire in two months to return to private life in Colorado, leaving President Barack Obama yet another cabinet vacancy to fill for his second term.

Salazar, 57, is the most prominent Latino in the president’s Cabinet. Previously, he’d served as a Democratic senator from Colorado following his 2004 election.

The resignation is the second in the environmental sector following the departure of Lisa Jackson, administrator of the Environmental Protection Agency, an African-American. Successors to both officials have yet to be named.

Salazar presided over the federal reaction to the 2010 Deepwater Horizon disaster by BP (NYSE:BP), as well as disputes over land use, Arctic Ocean drilling, fracking and mining as well as pushing for renewable energy on public lands.

“Ken has ensured that the department’s decisions are driven by the best science and promote the highest safety standards,” Obama said.