Since 1906 presidents of both parties have used the Antiquities Act to safeguard hundreds of millions of acres of federal lands as national monuments. Yet some Republicans have bitterly opposed certain designations in the last two decades, and the 2016 GOP platform called for amending the legislation to reduce the president’s authority to create monuments. Today President Trump will sign an executive order directing the Department of the Interior to review national monument designations made by his three predecessors. It’s no coincidence that the 21-year timespan of the monuments under review is bookended by two intensely criticized monuments in Utah—Grand Staircase-Escalante, declared by President Bill Clinton in 1996, and President Barack Obama’s designation of Bears Ears late last year. Members of Utah’s congressional delegation have been lobbying Trump to overturn Bears Ears for months. “I'm committed to rolling back the egregious abuse of the Antiquities Act,”...