President Trump has announced a substantial reduction in size of Utah's Bears Ears National Monument, a 1.35-million square acre swath of land that includes rock spires, canyons, mesas, mountains and sites significant to multiple Native American tribes.

The reduction is more than 80 percent of the monument's current size, shrinking it to 220,000 acres, according to CNN.

Another Utah monument, Grand Staircase-Escalante, will be reduced by 45 percent, shrinking the 1.9 million-acre monument to just over 1 million acres.

Bears Ears in the cross hairs

Established in December 2016 during the final days of the Obama administration, Bears Ears has been a political hot potato since before Donald Trump was elected president. The designation was declared a federal land grab by residents and Utah Republicans, where two-thirds of the state's lands are under federal control, and efforts to revoke the designation have been underway for some time.

According to a report by the Salt Lake Tribune, Sen. Orin Hatch (R-Utah), an opponent of the Bears Ears monument, met with Donald Trump Jr. days before the 2016 election and positioned his anti-monument cause as a "fight back against Washington overreach," laying the foundation for a concentrated effort by Utah Republicans to roll back, if not completely rescind, Obama's designation.

The Utah delegation presented Trump with a petition to revoke the designation, and a resolution from the Utah legislature, signed by the state's governor, asking for the same. According to the Tribune, Hatch's support for Trump's nominee for Secretary of the Interior, Ryan Zinke, was based entirely on whether or not Zinke would "work with [the Utah] congressional delegation to help us clean up the mess the Obama administration created in San Juan County," the senator said at the time, referring to Bears Ears.

The effort culminated in Hatch suggesting that the Trump administration go back further and review monument designations dating back all the way to 1996, when Grand Staircase-Escalante was declared a national monument during the Clinton administration. That resulted in now-Secretary Zinke reviewing about 27 monuments in August and recommending that at least six of the monuments reviewed have their boundaries changed in some fashion, including Bears Ears. Zinke's report did not make suggestions regarding the scope of the changes. It also made recommendations for the establishment of three new monuments, including one in Camp Nelson, Kentucky, where black soldiers trained during the Civil War.

Hatch alluded to the announced reduction in a Twitter video posted Nov. 30, saying it "strikes an excellent balance where everybody wins."

Legal challenges

The reduction in the size of the monuments is expected to set off legal battles that could challenge how land conservation is handled in the U.S.

National monuments differ from national parks in that parks are designated by Congress while the president has the authority to create monuments, thanks to the Antiquities Act of 1906. The law has been used by Democratic and Republican presidents to establish protected areas in the country. George W. Bush, for instance, used the act to establish the Mariana Trench, Pacific Remote Island and Rose Atoll marine national monuments at the end of his administration, a total of 125 million acres of protected ocean space.

The recent sticking point regarding the Antiquities Act, and especially in regards to Bears Ears, rests on the letter of the law that says a monument must be "confined to the smallest area compatible with proper care and management of the objects to be protected." When Obama established Bears Ears as national monument, he cited the area's historical and cultural significance to Native American tribes, including the Ute Mountain Ute Tribe, Navajo Nation, Ute Indian of the Uintah Ouray, Hopi Nation, and Zuni tribes, and Bears Ears' paleontological and ecological importance as reasons for declaring the land a monument.

The case, legal experts have argued, will rest on whether or not the Trump administration can prove that Bears Ears is too large for its intended purpose.

Bears Ears National Monument The Valley of the Gods at Bears Ears National Monument contains rock spires that are sacred to the Navajo, representing ancient warriors frozen in stone. (Photo: U.S. Bureau of Land Management)

Trump isn't the first president to reduce the size of a national monument. Woodrow Wilson shrank the size of Washington's Mount Olympus in 1915 by more than 313,000 acres, while Franklin Roosevelt reduced the size of the Grand Canyon monument by almost 72,000 acres in 1940. (Both sites are now national parks.) Despite the precedent established by such actions, the judicial system has never had to decide whether or not presidents have the authority to reduce the size of monuments established by their predecessors..

The Navajo Nation, along with other tribes and conservation groups, has already declared it will fight Trump's reduction of Bears Ears.

"We will stand and fight all the way," said Russell Begaye, president of the Navajo Nation, told The New York Times.

Shaun Chapoose, chairman of the Ute Indian Tribe business committee, told the Guardian that the announced reductions were "Another slap in the face in the overall relationship between the federal government and the tribes, and local people."

Any lawsuits that stop the reduction of Bears Ears would almost certainly cement presidential authority to create monuments and would ensure that such actions could not be undone by future administrations. A legal loss, however, would open the doors to presidents reducing the size of any monument and create an opportunity for many kinds of development on public lands.