Last week, President Donald Trump signed an executive order directing Secretary of the Interior Ryan Zinke to review all national monuments established since January 1996 and greater than 100,000 acres.

The president has the authority, pursuant to the 1906 Antiquities Act, to protect and preserve public lands through the designation of national monument status.

Trump prepared and signed the EO after many congressmen expressed concern that designation of national monuments occurs with little public and local involvement.

“We’re returning power back to the people … Today I’m signing a new executive order to end another egregious abuse of federal power, and to give that power back to the states, and to the people where it belongs,” Trump said at the signing ceremony.

About two dozen monuments will be reviewed, including six California monuments, of which two are in the Southern California desert. In February 2016, President Barack Obama designated three new national monuments — Mojave Trails National Monument, Castle Mountains National Monument and the Sand to Snow National Monument, which is in Riverside County.

The Castle Mountain National Monument is 20,920 acres and below the threshold for review.

The Sand to Snow National Monument connects the San Bernardino National Forest and Joshua Tree National Park. It encompasses about 154,000 acres, of which about 100,000 acres have already been designated as Congressional wilderness areas.

The Mojave Trails National Monument, encompassing nearly 1.6 million acres, of which more than 350,000 is already wilderness designated, is the largest of the three.

“This executive order does not remove any monuments. And this executive order does not weaken any environmental protections on any public lands,” Zinke stressed.

The EO directs Zinke to examine whether the designation was made without adequate public outreach and coordination with “relevant stakeholders.” A final report is due by the end of August

The designation of the two California monuments actually occurred after six years of study and efforts from U.S. Senator Dianne Feinstein (D-CA).

She had advocated protection for these lands for several years and had introduced legislation several times, including in 2015. In the absence of congressional action, Feinstein wrote Obama in the summer of 2015 requesting him to use the Antiquities Act authorities to designate the three monuments, which he did Feb. 12, 2016.

The Friends of the Desert Mountains has declared the Trump review “an unprecedented attack on our national monuments.”

After the enactment of the Antiquities Act in 1906, President Theodore Roosevelt used the authority to establish several new national monuments, including the Grand Canyon and Olympic National Park in Washington.

This is not the first time a president has had the secretary of interior review national monument designations made by a previous president. In 2001, President George Bush’s Interior Secretary Gale Norton reviewed several designations, which President William Clinton made. These were not changed following the review.