Interior Secretary Ken Salazar speaks during a ceremony in New Castle, Del., on March 26. (Patrick Semansky/AP)

The walls of Interior Secretary Ken Salazar’s office are nearly bare now: He has packed up his photos and most of his books, so only a few paintings remain. But tucked inside a desk drawer is an artifact from his more than four years in office: a small vial of oil recovered on July 14, 2010, from the BP oil spill in the Gulf of Mexico.

“I’m not sure if I’ll take it,” Salazar confessed, though he said the federal reforms and restoration funding stemming from the Deepwater Horizon disaster have left the country better off. “The legacy, of it, I think, is a positive one.”

In a 40-minute interview Wednesday reflecting on his time in President Obama’s Cabinet, Salazar said he was satisfied with his accomplishments. “I don’t know that I would have done anything differently,” he said. “I feel very good and very much at peace.”

Coping with the oil spill dominated his time during 2010, but Salazar said that the two agencies he created in its aftermath — the Bureau of Ocean Energy Management and the Bureau of Safety and Environmental Enforcement — meshed neatly with the “energy reform” he had hoped to undertake at Interior.

“I wanted to reform the department,” he said, adding that the Minerals Management Service, which had overseen offshore oil drilling at the time of the accident, “was archaic and needed to be overhauled.”

Salazar, who promoted renewable energy both on public lands and in federal waters, said he took over a department that had embraced a mind-set when it came to energy of “drill everywhere” and has brought balance to it.

And when it came to the question of allowing drilling in the Arctic Ocean, which many environmentalists oppose outright, the secretary defended his decision to allow Royal Dutch Shell to pursue exploratory activities there. Shell had to scale back its activities in the area this past summer because of unfavorable weather conditions and delays in acquiring permits, and has announced it will not drill on its ocean leases in 2013 because two of its vessels were damaged in Alaska over the winter.

“We wouldn’t allow them to drill into the hydrocarbons,” he said of Shell’s 2012 drilling season. “We did what we wanted to do this summer. We watched them carefully and didn’t let them move forward” when they hadn’t met federal requirements.

Salazar also touted the nine national monuments Obama has declared over the past four years, including five the president designated late last month. He described preserving those historic, cultural and environmental sites, including Colorado’s Chimney Rock and New Mexico’s Rio Grande del Norte, as acts that “will be seen as foundational to the conservation legacy of this president.”

Even as he has put away many of his belongings, Salazar still faces some uncertainty. He has not decided what job he will take next, though he plans to spend more time in Colorado with his family. And because Obama’s pick to replace him, REI chief executive Sally Jewell, has yet to be confirmed by the Senate, he “doesn’t have an end date yet.”

Even as he described the tight budget constraints the department is now experiencing under the mandatory, across-the-board cuts known as sequestration and the government’s funding by continuing resolution, Salazar said he still considered his post the best in the Cabinet.

“It’s a glorious job,” he said.