WASHINGTON (Reuters) - New Interior Secretary Ryan Zinke plans to review Obama-era measures that limited energy development on some federal land and undertake a “bold” reorganization of his 70,000-employee agency, he said on Friday.

New Interior Secretary Ryan Zinke tips his cowboy hat after riding in on horseback with a U.S. Park Police horse mounted unit reporting for his first day of work at the Interior Department in Washington, U.S., March 2, 2017. Tami Heilemann/Department of Interior/Handout via REUTERS

The former U.S. congressman addressed employees at the Department of Interior’s headquarters on his second full day on the job, assuring them he would not sell off federal lands, as some had feared, but also promising change.

“You can hear it from my lips: We will not sell or transfer public lands,” he said.

The department manages about a fifth of the country’s surface, including national parks, forests and tribal territories, from the Arctic to the Gulf of Mexico.

Zinke said he wanted to change the structure of the department, which includes the National Parks Service and the Bureau of Indian Affairs, to give more authority to rangers and land managers outside the District of Columbia.

“The last time the Department of Interior has been reorganized was about 100 years ago, so the reorganization is going to be bold,” he said.

Zinke, who arrived on horseback for his first day at the department, did not provide specifics but said he would rely on input from Interior’s sub-agencies and bureaus.

The ex-Navy SEAL said employee surveys showed the farther staffers were from Washington, the unhappier they were because “they felt they don’t have authority.”

Zinke, whose home state of Montana is one-third federal land, addressed career employees who face an uncertain future under Republican President Donald Trump. Some worry that Trump’s platform would open the door to selling off public land and more mining and drilling.

Others fear deep cuts to the agency’s budget. Zinke told staff he was “unhappy” about preliminary budget figures and would “fight” to secure more money.

Zinke has advocated for mining and drilling on federal land. He told reporters after his speech that he would review some executive actions from the waning days of the administration of former president Barack Obama, a Democrat, that had placed more federal land off-limits to development.

Those orders include limits to drilling in sensitive offshore areas like the Atlantic coast and Arctic, as well as a ban on new federal coal mining leases.

“I think I am going to review everything that didn’t go through Congress,” Zinke said.

However, he said the department would continue Obama’s effort to study whether coal leases had been properly valued to ensure taxpayers receive their fair value.

“I think we all benefit from that rather than buying a junk bond,” he said.