BILLINGS, Mont. (AP) — Montana Gov. Steve Bullock sued the Trump administration on Monday to block the acting director of the U.S. Bureau of Land Management from continuing in the position until he’s been confirmed by the Senate.

Federal law prohibits William Perry Pendley from leading the bureau in an acting capacity while his nomination last month by President Donald Trump is still pending, Bullock said.

The bureau, a branch of the Interior Department, oversees nearly a quarter-billion public acres in the U.S. West and much of the nation’s onshore oil and gas development.

Pendley is a former property rights attorney from Wyoming and longtime advocate for selling federal lands. He’s headed the bureau for the last year under a series of temporary orders that Democrats alleged were an attempt to skirt the nomination process.

Federal law prohibits acting directors from serving while their nomination is pending. Bullock’s lawsuit said Pendley’s “extreme, unpopular views on public lands” threatened to harm Montana’s natural resources, by placing extractive industries such as oil and gas exploration above conservation and the protection of declining species such as greater sage grouse.

Such policies “undercut the State’s ability to preserve and protect areas that have special fish and wildlife, archaeological, and recreational values,” the lawsuit said.

Administration officials called the lawsuit “nonsense.” Interior Secretary David Bernhardt has previously declared that Pendley was “exercising the authority of the director” but officials said Monday he was never formally named as the bureau’s acting director.

“This is a frivolous and politically motivated claim that has no legal standing,” Interior spokesperson Conner Swanson said.