President Trump signed an executive order (EO) Wednesday affecting the Antiquities Act of 1906, and potentially future oil and natural gas development, shortly after he and other Cabinet officials accused previous administrations of an “egregious abuse of federal power” in using the law to designate millions of acres as national monuments.

Language contained in the EO, including that certain monument designations may “create barriers to achieving energy independence,” strongly suggests that the Trump administration may ultimately decide to trim some of the national monuments created by the law. That could potentially reverse the exclusion of public land for various uses, including oil and gas development.

“The Antiquities Act does not give the federal government unlimited power to lock up millions of acres of land and water, and it’s time we ended this abusive practice,” Trump said in a signing ceremony at Department of Interior (DOI) headquarters in Washington, DC.

Under the EO, DOI Secretary Ryan Zinke will review certain prior monument designations and suggest legislative changes or modifications to the monuments. An interim report must be submitted to Trump within 45 days of the EO’s signing, and a final report is due within 120 days.

Specifically, Zinke is to review monument designations made since Jan. 1, 1996 for areas totaling 100,000 acres or more. In a separate interview Tuesday night, Zinke said the EO would include between 24 and 40 monuments in total. The timeframe would include more than half of the designations made during the Clinton administration, and the entire administrations of George W. Bush and Barack Obama.

The EO specifically mentioned the Bears Ears National Monument in southeast Utah. Last December, President Obama used the Antiquities Act to create two new national monuments— Bears Ears and the Gold Butte National Monument in Nevada. Obama set aside 1.35 million acres for Bears Ears.

Trump said the Bears Ears’ designation was made “over the profound objections of the citizens of Utah.” He added that the EO was necessary “to end another egregious abuse of federal power and to give that power back to the states and to the people, where it belongs.”

Trump blasted the Obama administration for having “unilaterally put millions of acres of land and water under strict federal control, eliminating the ability of the people who actually live in those states to decide how best to use that land. Today we’re putting the states back in charge…

“Altogether, the previous administration bypassed the states to place over 265 million acres…of land and water under federal control through the abuse of the monuments designation. That’s larger than the entire State of Texas.”

Shortly before Trump took the podium, Zinke said the Antiquities Act “has become a tool of political advocacy, rather than public interest, and it’s easy to see why designations in some cases are viewed negatively by those in local communities who are impacted the most.” He later stressed that the EO “does not remove any monuments [or] weaken any environmental protections on any public lands.”

Between comments by Zinke and Trump, Vice President Mike Pence said the EO would “undo one of the great federal overreaches of recent decades: the abuse of the Antiquities Act by politicians in Washington, DC, to grab land and power at the American people’s expense.”

Republican senators attending the signing ceremony were Orrin Hatch and Mike Lee of Utah and Lisa Murkowski of Alaska. GOP Govs. Gary Herbert of Utah, Paul LePage of Maine, Eddie Calvo of Guam and Ralph Torres of the Northern Mariana Islands were also present.

Bears Ears is in San Juan County, UT, which has seen mostly conventional but also some unconventional oil and gas drilling. The county overlays the Paradox Basin, which includes the Cane Creek and Hovenweep shales.

In the Tuesday night interview, Zinke said previous administrations have used the Antiquities Act to set millions of acres aside from “traditional uses, like farming, ranching, timber harvest, mining, oil and gas exploration, fishing, and motorized recreation.”

“My obligation is to wrap up at least my recommendation in 120 days,” Zinke said, according to a transcript provided by C-SPAN. “The recommendation I could save for further review…I have some latitude as the secretary to look at whether I have the facts on the ground.” He added that Trump isn’t planning to sell or transfer public lands. “This EO simply initiates a review, which is appropriate.”

Trump is reportedly expected to sign another EO on Friday ordering federal agencies to review areas available for offshore oil and gas exploration, and to review rules governing offshore drilling.