U.S. President Donald Trump holds up a signed Antiquities Executive Order during a ceremony at the Interior Department in Washington, April, 26, 2017.
U.S. President Donald Trump holds up a signed Antiquities Executive Order during a ceremony at the Interior Department in Washington, April, 26, 2017.

LOS ANGELES - President Donald Trump has signed an executive order to review the protected status of national monuments created on the land and in the ocean over the past 20 years.

Trump says the move returns federal lands to the people, while critics say it could open two dozen protected natural areas to potential development.

“Today I'm signing a new executive order 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 said as he signed the executive order at the Department of the Interior in Washington.

The sites are mostly in the Western United States, and include venues given protected status by former Presidents Bill Clinton, George W. Bush and Barack Obama. Each invoked the Antiquities Act of 1906, which was signed into law by President Theodore Roosevelt.

FILE - In this June 22, 2016 photo, the "House on
FILE - In this June 22, 2016 photo, the "House on Fire" ruins is shown in Mule Canyon, near Blanding, Utah in Bears Ears National Monument.

Review of monuments opposed

Major sites under review include the Grand Staircase-Escalante National Monument and Bear Ears National Monument in Utah.The 500,000 hectare Bears Ears site is home to Native Americans, who oppose the review.

Carleton Bowekaty, a Zuni tribal official and co-chair the Bears Ears Inter-Tribal Coalition, said in a statement that five Native American nations oppose any change to the status of “this sacred cultural landscape that carries deep meaning for our people.”

The Trump administration tried to reassure the critics.

“Let's be clear,” said Interior Secretary Ryan Zinke. “This executive order does not remove any monuments. And this executive order does not weaken any environmental protections on any public lands.”

Interior Secretary Ryan Zinke speaks at the Interi
Interior Secretary Ryan Zinke speaks at the Interior Department in Washington, April 26, 2017, before President Donald Trump signed an Antiquities Executive Order.

Decisions made without full review

Some Republicans and land-use activists have chafed at the restrictions on large swaths of federal land that have been shielded from development, including extraction of resources such as minerals, natural gas and oil.

Trump said recent designations under the century-old law have deprived the public of economic benefits, and were done without full review.

Not so, the critics say.

“This isn't an issue of economic impacts or lack of public process,” Peter Shelley, senior counsel with the Conservation Law Foundation, said. “This really is part of an agenda to roll back protections on some of our most precious resources for economic development purposes.”

“Under the law and congressional intent, only Congress can modify or revoke a monument,” a designation that protects sites of scientific, historic or archeological interest, Shelley said. Most adjustments in the past have been to correct faulty boundaries from initial surveys or inaccurate maps, he added.

Watch: Trump Orders Review of National Monuments

Courts may have last word

Potential changes sought through the review would likely be controversial and probably would be decided by the courts.

Opinion surveys show national parks and monuments are highly popular with the American public.

As he signed the order Wednesday, Trump said some of his actions may not be popular, but he believes he is doing the right thing.