Trump is reviewing 6 California national monuments. Here's how to weigh in.

Under an executive order from President Donald Trump, the U.S. Department of Interior has begun a sweeping review of 27 national monuments, including six in California. The review could mean some monuments will be altered or eliminated altogether. The public has until July 10 to comment on what changes, if any, should be made to the monuments. 

To make a comment, go to regulations.gov.

In California, the national monuments under review stretch from the Mojave Desert to the coastal range in Mendocino County. All were created by Presidents Obama and Clinton using the Antiquities Act, a law that allows presidents to use their executive power to give additional protections to land already managed by the federal government. Trump is now seeking to alter the boundaries of some of those monuments, or eliminate some outright. Two Utah monuments are particularly controversial, Bears Ears and Grand Staircase Escalante.

Conservationists are worried.

"There is no predictability about what this administration’s going to do," said The Wilderness Society's Daniel Rossman, who is based in Los Angeles and worked on the establishment of San Gabriel Mountains National Monument. "We’re on high alert."

Among the national monuments in Southern California, Mojave Trails in San Bernardino County appears to be most at risk, according to Danielle Segura, executive director of the Mojave Desert Land Trust.

The monument, which encompasses sand dunes, lava flows and craggy mountains, surrounds a large section of private land where the water company Cadiz Inc. has been trying for over a decade build a controversial groundwater pumping project. The project stalled in 2002, but has recently been revived by the Trump administration's Bureau of Land Management.

Cadiz spokeswoman Courtney Degner said the company has no position on the monument review but hopes all local voices and opinions are respected in the process. The company's website says Cadiz does oppose the way the monument was created. "In our view, a locally-developed, Congressional solution ...  is greatly preferred by the local, affected communities and is more likely to be successful over the long-term than a unilateral presidential action," according to the website.

Cadiz could get a serious ally in the Department of Interior if natural resources attorney David Bernhardt is confirmed next week as deputy Secretary of Interior. His law firm would gain $3 million if the project wins federal approval, according to the Center for Western Priorities.

Segura worries the water project could dry up springs and seeps within the national monument that are important for bighorn sheep and other desert wildlife. 

"Where they're drawing the water from extends far beyond the actual project area," she said.

Closer to LA, supporters of the San Gabriel Mountains National Monument are also concerned about the Trump Administration's review.

Omar Gomez, the chair of the San Gabriel Mountains Forever Coalition, says because the mountains are the source of much of greater Los Angeles' local drinking water supply, it is critical to maintain a high level of protection. He is particularly concerned about a possible increase in prospecting and mining.

Ron Kliewer, who represents the mining advocacy group Public Lands for the People, filed a public comment indicating he would like to see all California monuments with significant mineral potential, including the San Gabriel Mountains and Mojave Trails, overturned.