Hawaii Attorney General Russell A. Suzuki joined 10 other states in filing two amicus curiae, or “friend of the court” briefs, challenging President Donald Trump’s proclamations to drastically reduce the size of two national monuments in Utah.

The lawsuits, filed to U.S. District Court for the District of Columbia argue that President Trump’s attempt to eliminate 85 percent of Bears Ears and approximately half of Grand Staircase-Escalante from the monuments is illegal. Suzuki says doing so would effectively rescind a national monument for the first time in U.S. history.

“The President does not have the authority to rescind a national monument and we stand with our colleagues to protect these treasures,” Suzuki said in a statement.

In the briefs, the states assert the monument reductions overstep presidential authority and upend the purpose of the Antiquities Act of 1906, which delegated authority to the president to preserve the nation’s archaeological, historical and scientific resources as national monuments rather than to revoke or reduce those protections.

No date has yet been set for oral argument by the U.S. District Court.

Washington State took the lead on filing the briefs and was joined by Hawaii, California, Maine, Maryland, Massachusetts, New Mexico, New York, Oregon, Rhode Island and Vermont.