President Trump on Monday afternoon announced he will shrink Utah’s Bears Ears and Grand Staircase-Escalante national monuments, framing the decision as a sharp rebuke of former President Barack Obama's use of executive authority to set aside public land for protection.

"With the action taken today we will not only give back your voice to use of the land, we will also restore your access and enjoyment," Trump said during a ceremony at the state capitol in Salt Lake City. "Public lands will once again be for public use. Families and communities of Utah know and love this land the best, and you know the best how to take care of your land and how to conserve this land for many generations to come."

He then signed two proclamations to shrink the monuments. He is reducing the 1.35-million-acre Bears Ears, established by Obama, to 201,876 acres, and Grand Staircase, created by former President Bill Clinton in 1996, from 1.7 million acres to 1 million.

Trump did not visit the monuments themselves, which are hours away from the capitol. If the moves survive anticipated legal challenges, they would represent the largest removal of national monument protection in U.S. history.

Obama created Bears Ears just before he left office, protecting a vast area of mesas and canyons in Utah's poorest county. It is an area in the southeastern part of the state that five Native American tribes consider sacred and depend on for sustenance and cultural tradition.

Trump, shortly after his inauguration, ordered Interior Secretary Ryan Zinke to undertake a review of 27 national monuments created since 1996. In August, Zinke delivered the report to Trump, recommending he reduce the size of six of those monuments, including the two in Utah. Zinke told reporters he will make the report public Tuesday.

The president’s actions are a win for Republicans and most of Utah’s political delegation, who say previous presidents abused their authority under the 1906 Antiquities Act to unilaterally declare national monuments, by setting aside larger and larger swaths of public land, limiting development opportunities and stifling local control.

“I've become an expert in monuments and the Antiquities Act was never intended to prevent. It was intended to protect,” Zinke said in remarks at the state capitol. "Our public land is for the public to use and not special interests. This is about giving rural America a voice."

Republican Sens. Orrin Hatch and Mike Lee of Utah joined Trump and Zinke on Air Force One from Washington to Salt Lake City.

House Natural Resources Chairman Rep. Rob Bishop of Utah, whose committee passed legislation this year to limit the Antiquities Act, also attended Trump's announcement.

A national monument designation prohibits prospective mining and drilling on the land, although existing leases for energy extraction are maintained.

They are similar to national parks, but those are created by Congress. Bears Ears’ monument designation forbid new mining and drilling, but allowed the Interior Department to issue leases for cattle grazing.

Zinke said reducing the size of the Utah monuments would permit greater use of the area for public access to roads, grazing, and active management for conservation, hunting, fishing and recreation.

Naming a national monument through the Antiquities Act, which was signed into law by President Theodore Roosevelt in 1906, has historically received bipartisan support. Eight Democratic presidents and eight Republicans have used the law in some form, according to the Wilderness Society.

While Republicans complained about Obama's use of the law, many Democrats endorsed the designation and expansion of monuments, and said it provides needed protection to some of the nation's pristine landscapes, culturally important places and threatened animal and plant habitats.

"Veterans, sportsmen, climbers, hikers and the outdoor economy all depend on open space,” said Sen. Maria Cantwell of Washington, the top Democrat on the Senate Energy and Natural Resources Committee. “Bears Ears and Grand Staircase-Escalante have been driving a vibrant outdoor economy for years. Now President Trump is using unlawful authority to pollute these special places. His administration deserves an 'F' for stewardship."

The Antiquities Act, however, specifies that national monuments should cover "the smallest area compatible with proper care and management of the objects.”

Under Trump’s proposal, Bears Ears would be divided into two smaller, monuments: Indian Creek National Monument and the Shash Jaa National Monument.

Grand Staircase-Escalante would be split into three areas: Grand Staircase National Monument, Kaiparowits National Monument, and Escalante Canyons National Monument.

Environmental groups and tribes, including the Navajo Nation, have already said they will sue the Trump administration for shrinking national monuments, and several Democratic attorneys general, most in the West, have vowed to challenge the actions.

Supporters of the monuments note the Antiquities Act does not explicitly give authority to presidents to reduce the size of national monuments, although some have done so on a limited scale. The concept has not been tested in court.