President Donald Trump on Monday cut the dimensions of two national monuments in Utah, reversing safeguards put in place by prior Democratic leaders on public lands viewed as sacred by numerous Native American groups.

Bears Ears and Grand Staircase-Escalante national monuments in southern Utah feature ancient cliff dwellings, rock carvings and scenic canyons, along with coal and uranium deposits that state leaders seek to open for development.

Trump, a Republican, signed proclamations under the Antiquities Act to shrink each monument by roughly 90 percent. He pursued comparable steps in his initial term, yet those changes were overturned by President Joe Biden, a Democrat.

The current action occurs as Trump and fellow Republicans have broadly altered oversight of extensive taxpayer-owned lands mainly located in Western states. Trump administration officials and congressional Republicans have aimed to increase drilling, mining and logging on public lands, while easing protections for endangered species and relaxing conservation standards.

"They took the land from the people quite honestly," Trump stated during a signing event at the White House on Monday. "We're giving it back."

President Bill Clinton, a Democrat, created Grand Staircase-Escalante National Monument in 1996, and President Barack Obama, also a Democrat, established Bears Ears National Monument in 2016 under the Antiquities Act. The 1906 statute grants presidents authority to safeguard locations deemed historic, archaeologically notable or culturally significant.

Davina Smith-Idjesa, a Navajo Nation citizen and co-chair of the Bears Ears Inter-Tribal Coalition, noted that tribal leaders had prepared for reductions since Trump's reelection. She described the decision as "heartbreaking" and charged federal officials with bypassing their duty to consult affected tribal nations.

"From a Navajo perspective, Bears Ears is not simply a piece of federal public land," Smith-Idjesa said. "This is a living cultural site that holds our histories, our ceremonies, our traditional foods and medicines and our ancestors' footprints."

Utah leaders have long opposed the monument designations and contended that the state should control its own lands. Trump in his first term reduced their size, labeling their creation a "massive land grab." Together they covered more than 3.2 million acres (13 million hectares), an area close to the size of Connecticut.

Trump reduced them Monday to under 303,000 acres (123,000 hectares) combined.

That represents a larger cut than in his first term, when he retained Grand Staircase-Escalante at 1 million acres (405,000 hectares) and Bears Ears at 213,000 acres (86,000 hectares).

"This is a big day for Utah," Utah Gov. Spencer Cox said while standing beside Trump at the White House. "These monument designations are supposed to be the smallest area as possible to protect the antiquities."

Bears Ears was the first national monument created at the request of tribal nations that regard the land as sacred. The area includes ancestral villages, ceremonial and burial sites and elements in some tribes' creation and migration stories. Its designation recognized five tribes in the region - Navajo, Hopi, Zuni, Ute Mountain Ute and Uintah-Ouray Ute.

Home to hundreds of thousands of objects of cultural and scientific importance, Bears Ears is jointly managed through an agreement between tribal nations and federal agencies.

Grand Staircase-Escalante includes cliffs, canyons, natural arches and archaeological sites, including rock paintings. It contains large coal reserves, while the Bears Ears area holds uranium.

The national monument designation offers broad protections not only for key geological features or artifacts but also for the surrounding landscape, prohibiting drilling, mining and new construction nearby. Supporters of Trump's decision to reduce the size argue that the protective boundaries extend too far and impede mining for critical minerals.

Trump claimed Monday that people cannot hunt, fish or "virtually not even walk" on the monuments. That is incorrect: Hunting, fishing, camping and other recreation remain allowed under state and federal regulations, said Steve Bloch, legal director for the Southern Utah Wilderness Alliance, a conservation group.

Biden designated or expanded more than a dozen monuments and set a target to conserve at least 30 percent of U.S. lands and waters by 2030.

Trump's policies run largely counter: He seeks to access the natural resource wealth of federal lands that total more than 100,000 square miles (260,000 square kilometers) and offshore areas under federal control, such as in the Gulf of Mexico and off Alaska.

That has prompted criticism from Democrats who caution against the broad release of valued landscapes for commercial purposes.

"Today's executive action is another chapter in this administration's war on the West," Democratic Sen. Martin Heinrich of New Mexico said Monday. He added that Trump was "turning the Antiquities Act on its head."

Trump Interior Secretary Doug Burgum said last year that federal officials would review and consider redrawing monument boundaries as part of a push to expand U.S. energy production.

Trump in his current term has used proclamations to lift commercial fishing prohibitions within expansive marine monuments in areas of the Pacific Ocean and in the Atlantic Ocean off the New England coast. Those monuments were created by Democratic and Republican administrations. The effort to boost the fishing industry, which has been challenged in court, marks a dramatic shift in federal policy by prioritizing commercial interests over efforts to allow the fish supply to increase.

Some Republicans have attempted to sell or transfer federal lands to states or other entities. Those efforts have largely failed: A push by some GOP lawmakers in the House to sell public lands encountered bipartisan opposition, while another proposal by Sen. Mike Lee of Utah to sell more than 3,200 square miles (8,300 square kilometers) of federal lands was removed from Republicans' big tax and spending bill.

The U.S. Supreme Court last year rejected a lawsuit from Utah officials who sought to gain control of vast areas of public land within the state from the federal government.

Hannah Schoenbaum reported from Salt Lake City.