WASHINGTON — President Donald Trump plans to sign an executive order today directing his interior secretary to review the designation of tens of millions of acres as “national monuments,” an action that could upend protections put in place in Utah and other states as Trump tries to rack up accomplishments in his first 100 days.

The Antiquities Act of 1906 authorizes the president to declare federal lands as monuments and restrict how the lands can be used.

“The executive order will direct me as the secretary to review prior monument designations and to suggest legislative changes or modifications to the monuments,” Interior Secretary Ryan Zinke told reporters Tuesday evening.

While Zinke acknowledged criticism that the act has been overused by past presidents, he insisted he’d approach the topic with an open mind.

“I’m not going to predispose what the outcome is going to be,” he said.

Former President Barack Obama infuriated Utah Republicans when he created the Bears Ears National Monument in late December on more than 1 million acres that’s sacred to Native Americans and home to tens of thousands of archaeological sites, including ancient cliff dwellings.

Republicans in the state said it was an egregious abuse of executive power and have asked Trump to take the unusual step of reversing the designation, arguing it will stymie growth by closing the area to new commercial and energy development. The Antiquities Act does not give the president explicit power to undo a designation and no president has ever taken such a step.