WASHINGTON (Reuters) - U.S. President Donald Trump has signed an executive order to allow national monument designations to be rescinded or reduce the size of sites as the administration pushes to open up more federal land to drilling, mining and other development.

Trump’s order is part of an effort to reverse many of the environmental protections implemented by his predecessor, Democratic President Barack Obama that Trump said were hobbling economic growth. Trump’s agenda is being cheered by industry but enraging conservationists.

Legal challenges are expected because no president has ever rescinded a monument designation.

In announcing the order on Wednesday Republican Trump said Obama’s use of the 1906 Antiquities Act to create monuments was an “egregious abuse of federal power” that allowed the federal government to “lock up” millions of acres of land and water.

The Antiquities Act gives a president the authority to create national monuments from federal lands to protect significant natural, cultural, or scientific features.

“Today we’re putting the states back in charge,” Trump said, adding that they should decide which land is protected and which is open for development.

Interior Secretary Ryan Zinke told reporters late Tuesday the order requires him to review about 30 national monuments created over the past two decades, and recommend which designations should be lifted or altered.

The monuments covered under the review will range from the Grand Staircase created by President Bill Clinton in 1996 to the Bears Ears created by Obama in December 2016, both in Utah.

Zinke said he will seek local feedback before making recommendations, adding that reversing a monument designation could be tricky.

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“It is untested, as you know, whether the president can do that,” Zinke said.

President Woodrow Wilson reduced the size of Washington state’s Mount Olympus National Monument in 1915, arguing there was an urgent need for timber at the time.

Zinke said he will review the Bears Ears monument first and make a recommendation to the president in 45 days. He has 120 days to issue a full report on all monuments to the president. Bears Ears protects Native American cultural heritage and sacred sites.

Obama created the Bears Ears monument in the final days of his administration. Utah’s governor and the state’s congressional delegation opposed the designation, saying it was done against the wishes of citizens eager for development.

Utah Governor Gary Herbert, and Senators Mike Lee and Orin Hatch, all Republicans, stood beside Trump as he signed the order. Trump said the lawmakers lobbied him for the order.

Bears Ears is near where Texas-based EOG Resources Inc has been approved to drill.

Republican House of Representatives Speaker Paul Ryan praised the order.

“I commend the Trump administration for stopping this cycle of executive abuse and beginning a review of past designations,” he said.

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Conservation and tribal groups were critical.

“With this review, the Trump Administration is walking into a legal, political and moral mine field,” said Kate Kelly, public lands director for the Center for American Progress.

Democratic Congressman Raul Grijalva of Arizona, ranking member of the House Natural Resources Committee, warned Zinke not to make an “ideological” decision. He said previous monuments were decided “after years of close federal consultation with multiple local stakeholders.”

The five Native American tribes that pushed to create the Bears Ears monument to protect ancestral land said they will fight to protect it.

The Outdoor Industry Association, the trade group of the recreation industry, also attacked the order.

The group has estimated the outdoor recreation economy generates over $887 billion in consumer spending and creates 7.6 million jobs.

“Less than 24 hours after joining with our industry to celebrate the economic power of outdoor recreation, in a hypocritical move, the Trump administration took unprecedented steps that could result in the removal of protections for treasured public lands,” said Rose Marcario, chief executive of outdoor gear retailer Patagonia.

On Friday, before the close of Trump’s first 100 days in office, he is expected to sign an executive order that would review offshore areas available for offshore oil and gas exploration that have been restricted by previous presidents.

(This version of the story has been refiled to delete extraneous text in paragraph 17)