Bernhardt is a former lobbyist for oil and gas companies.
Zinke played a leading part in Trump’s efforts to roll back environmental regulations and promote domestic energy development.
U.S. District Judge Brian Morris is presiding over a Thursday hearing on whether the moratorium should be reinstated.
The Interior Department plans to ease restrictions on oil and natural gas drilling and other activities across millions of acres in the American West.
Like his boss, Bernhardt's position hasn't come with controversy or conflicts of interest.
The Interior Secretary touts that the overhaul would move employees out of D.C. Some Democrats have called the plan unworkable.
The lawsuit claims that Secretary of the Interior Ryan Zinke and the BLM didn’t properly assess the environmental impact of drilling on the land.
A decision about whether to move the BLM and where isn’t expected for many months.
The Secretary of the Interior was making an appearance at a private event sponsored by the conservative Steamboat Institute’s Freedom Conference.
The Center for Biological Diversity, a conservation group, said Sheehan’s departure was “welcome news for America’s wildlife.”