Last Updated Dec 4, 2017 3:40 PM EST
SALT LAKE CITY, Utah -- The landscape ofhas served as a vital resource for thousands of years to those living in southeastern Utah.
According to the U.S. Forest Service, Bears Ears — which sprawls across more than 1.3 million acres — acts as a home to animal and plant life. Tribes have been able to collect plants and firewood within the monument. And over the past 200 years, ranchers, miners, Mormon pioneers and homesteaders have traveled within the area.
Sixteen presidents have exercised the 1906 Antiquities Act, which gives the president broad authority to declare federal lands as monuments and restrict their use, to protect some of America's most historic monuments, including the Grand Canyon and the Statue of Liberty, according to the U.S. Forest Service.
signed proclamations Monday to formally downsize Bears Ears, as well as Grand-Staircase Escalante. Thousands have protested his decision.
Trump's monument reduction plan
Mr. Trump traveled to Salt Lake City on Monday where he signed the proclamations, responding to what he has condemned as a "massive federal land grab" and an important move for "state's rights."
The move was supported by Utah's top Republican officials, but opposed by tribes and environmental groups.
Mr. Trump said in a speech Monday at the Utah State Capitol that past presidential administrations had "severely abused" the purpose and spirit of a federal law that allows them to protect public lands by turning them into national monuments.
Mr. Trump said his action means that "public lands will once again be for public use."
The two national monuments were among 27 that Mr..
Utah's Republican leaders, including Sen. Orrin Hatch, pressed Mr. Trump to launch the review, saying the monuments declared by Presidents Barack Obama and Bill Clinton locked up too much federal land.
Mr. Trump's plans to curtail the strict protections on the sites have angered tribes and environmentalist groups who have vowed to sue to preserve the monuments.
In December, shortly before leaving office, Obama irritated Utah Republicans by creating the Bears Ears National Monument on 1.35 million acres of land sacred to Native Americans and home to tens of thousands of archaeological sites, including ancient cliff dwellings.
Mr. Trump signed an executive order in April directing Zinke to conduct a review of the protections. Mr. Trump is able to upend the protections under the Antiquities Act.
The president said in April his order would end "another egregious abuse of federal power" and "give that power back to the states and to the people where it belongs."
Mr. Trump said at the time that he had spoken to state and local leaders "who are gravely concerned about this massive federal land grab. And it's gotten worse and worse and worse, and now we're going to free it up, which is what should have happened in the first place. This should never have happened."
The move marks the first time in a half century that a president has attempted to undo these types of land protections. And it could be the first of many changes to come.
Zinke also has recommended that Nevada's Gold Butte and Oregon's Cascade-Siskiyou monuments be reduced in size, although details remain unclear. The former Montana congressman's plan would allow logging at a newly designated monument in Maine and more grazing, hunting and fishing at two sites in New Mexico.
Democrats and environmentalists have opposed the changes, accusing Trump and Zinke of engaging in a secretive process aimed at helping industry groups that have donated to Republican campaigns.