This week US president Donald Trump used his executive powers to make unprecedented cuts to 2 million acres of land at two national monunemt sites in Utah.
The The Bears Ears monument will lose 85 percent of its total area and the Grand Staircase-Escalante will be reduced by 45 percent as protections against development and agriculture will be removed.
Announcing the decision in Salt Lake City, Trump said the move would restore the land to citizens and also hinted at the economic benefits of developing the area.
But, as Brian Resnick explains for Vox, the president is moving into legally uncharted territory:
"Five Native American tribes — the Navajo Nation, Hopi, Ute Mountain Ute Tribe, Ute Indian, and Pueblo of Zuni — have joined in a lawsuit against the Trump administration, charging that the president of the United States has no power to decrease the size of national monuments like Bears Ears."
10 environmental groups have brought a similar case relating to Grand Staircase-Escalante.
Reductions to national monuments have been made before, by Woodrow Wilson and Franklin D Roosevelt, but not to this scale, and neither were challenged in court.
The cases will hinge on the 1906 Antiquities Act, which grants the president powers to preserve historic or pre-historic sites, but does not mention the removal of these protections. Resnick writes:
"The result of the expected legal challenges will have far-reaching consequences. They’ll clarify the degree to which a president can undo conservation efforts ... National monument designations are meant to ensure consistent protection for public lands. If courts favor Trump, then those protections could become fleeting."