President Trump announced Monday that he will nominate David Bernhardt, a veteran lobbyist who has helped orchestrate the administration’s push to expand oil and gas drilling as the Interior Department’s number-two official, to serve as the next secretary.

If confirmed, Bernhardt, a 49-year old Colorado native known for his unrelenting work habits, would be well positioned to roll back even more of the Obama-era conservation policies he has worked to unravel since joining Interior a year and-a-half ago. He has helmed the department as acting secretary since Jan. 2, when Ryan Zinke resigned amid multiple ethics probes.

“David has done a fantastic job from the day he arrived, and we look forward to having his nomination officially confirmed!,” Trump tweeted.

While Zinke reveled in public displays of his affinity for the outdoors—riding horseback while on the job, touting his enthusiasm for hunting and experience as a Navy SEAL—Bernhardt is the ultimate insider. A former Capitol Hill staffer who served as Interior’s top lawyer under George W. Bush, Bernhardt has made it his mission to master legal and policy arcana in order to advance conservative policy goals.

In an interview last year with The Post, Bernhardt said he immerses himself in the details of every significant policy decision because he knows that decisions made in Washington have enormous ramifications for Americans across the country.

“I don’t shy away from reading a massive amount of material before decision,” he said. “And I don’t, for a minute, not think about the impact that it’s going to have for good or ill.”

While Bernhardt has deliberately adopted a low-profile while steering the 70,000-person department, he has used his expertise to promote the president’s agenda at every turn. He is working to streamline environmental reviews to expedite energy projects, and has promoted overhauling the Endangered Species Act to provide more certainty to developers.

During the 35-day shutdown, Bernhardt employed novel tactics to ensure oil and gas drillers could continue to obtain permits and national parks would stay open even as most of the department was shuttered. When trash piled up and human waste began posing a health risk at popular national parks, for example, Bernhardt instructed superintendents to tap fees these sites had collected to address their most visible problems.

The push to keep Interior’s energy divisions on track during the budget impasse on track won praise from trade groups like the National Ocean Industries Association.

“The offshore energy industry generates billions of dollars for the U.S. and state treasuries, provides thousands of well-paying jobs in the U.S. and bolsters our national energy security,” the group’s president Randall Luthi said at the time, referring to preparations underway for a March offshore lease sale. “It makes both economic and energy sense to continue work on this long-planned and approved sale.”

And Kathleen Sgamma, president of the Western Energy Alliance, praised Bernhardt in an email Monday as someone with “a deep understanding of public lands issues” who would be “an excellent choice” to head Interior.

Initially Bernhardt was reluctant to take the post when approached by the White House, according to administration officials who spoke on the condition of anonymity in order to discuss personnel matters. But the shutdown, coupled with Zinke’s departure, also gave Bernhardt an opportunity to spend more time with the president as Trump weighed how to fill the vacancy.

During a Cabinet meeting last month, Bernhardt sat next to the president, and he also accompanied Trump and Pence on a recent trip to the Martin Luther King Jr. memorial on the Mall.

Bernhardt’s industry-friendly policies, coupled with his extensive work as a lobbyist, have earned him the enmity of environmental groups and many Democrats.

A former partner at Brownstein Hyatt Farber Schreck, he initially had to recuse himself from “particular matters” directly affecting 26 former clients in order to confirm with the Trump administration’s ethics pledge. He continues to carry around a small card in his suit pocket listing all of his current recusals, to underscore his commitment to adhering to the law.

“I talk to ethics experts, and I’m very careful, but I am 100 percent in compliance,” he said in an interview. “There’s not even a question about it.”

But liberal advocacy groups like the Western Values Project, which targeted Zinke while in office, have argued Bernhardt’s lobbying past disqualifies him for serving in Interior’s top post. On the day Trump announced Zinke would step down, the group launched a website to highlight Bernhardt’s work in the private sector.

“The bottom line is that Bernhardt is too conflicted to even be Acting Secretary,” said Western Values Project executive director Chris Saeger. “At the very least the American public deserved to know more about the man behind the curtain who is actually running the show at Interior and could soon be fully responsible for managing our country’s public lands, wildlife and natural resources.”

The head of one centrist conservation group, the Theodore Roosevelt Conservation Partnership, said in an email Monday that his organization would back Bernhardt despite their policy differences.

“He has been a steady hand during challenging times at the Department and he has worked to strengthen relationships with the states and the nation’s sportsmen and women.,” said the group’s president, Whit Fosburgh. “Mr. Bernhardt’s nomination to be Secretary of the Interior places him in an unenviable position to balance the priorities of the Trump Administration with the mission of the Department.”

Even Bernhardt’s opponents, however, described him as a skilled policy and legal expert who has spearheaded the regulatory rollbacks and accelerated oil and gas leasing at a department that manages 500 million acres of U.S. land.

In the last two years Interior has auctioned off more than 16.8 million acres of public land for oil and gas drilling, according to the advocacy group Center for Biological Diversity, 2.3 million of which was sold. In the first quarter of 2019, nearly 2.3 million more acres are on the chopping block.

Bernhardt has played a key role in shrinking two national monuments in southern Utah, as well as pushing to open up the land now outside their boundaries to be opened up for coal and mineral mining. While opponents of the move came to public comment meetings at Bureau of Land Management offices in October, Bernhardt dismissed that criticism as coming from out of state, including California.

While Zinke took extensive personal time while serving as secretary and traveled frequently to his homes in Whitefish, Mont. and Santa Barbara, Calif., Bernhardt has spent much of his time in office working at headquarters or at home in northern Virginia.

Dan DuBray, who worked for Bernhardt on Indian trust issues during the Bush administration and retired last year as the U.S. Bureau of Reclamation’s director of public affairs, said his former boss was focused on maximizing efficiency even as they toured some of America’s most scenic sites.

“We’d have long days, in Portland, Anchorage and Arizona, I think David was still game to keep going, others might have wanted to see a local site or get outside,” DuBray said. “There’s a finite amount of time, and David has always been keenly aware of that–we have limited time to get our agenda accomplished.”

While Bernhardt has made a point of consulting with Republican lawmakers since returning to Interior, his support among congressional Democrats has slipped since he was confirmed. The Senate approved him as deputy secretary on a vote of 53 to 43, largely along party lines. While the Republican margin of control in the Senate all but ensures that he will win confirmation, he is unlikely to attract as much Democratic support as he did a year and-a-half ago.

House Natural Resources Committee Chairman Raul Grijalva (D-N.M.) has already indicated he intends to call Bernhardt before his panel to testify about some of the department’s policy decisions, and confirmation hearings in the Senate would allow Democrats to press for answers on an array of fronts.

Bernhardt, for his part, has made an effort to reach out to Interior staff through a series of occasional department-wide emails. On Sunday he sent an email praising their dedication, even as he blasted Obama administration officials for not upholding the department’s ethical standards.

“I believe that serving the public is one of the highest callings a person can undertake,” he wrote in an email Sunday, which was obtained by The Washington Post. “This belief has been reaffirmed in the past few weeks as many of you carried on fulfilling the Department’s mission with the knowledge that the timing of your pay was highly uncertain. This perspective is why the notion that a public servant would breach the public trust to enrich themselves so deeply offends me. Such conduct undermines everything I believe in regarding public service.”