Eight national monuments created in California over the past two decades will be reviewed under an executive order signed Wednesday by President Trump that second-guesses designations covering more than a billion acres nationwide. During a signing ceremony Wednesday, Trump called Obama’s monument designations a “land grab” and said the order is designed to “end another egregious abuse of federal power, and to give that power back to the states and to the people, where it belongs.” The president ordered Interior Secretary Ryan Zinke to evaluate each site designation for its compatibility with the original intent of federal law and its effect on the public’s use and access. “We’re treating this as the opening salvo of a full-scale attack on national monuments,” said Dan Hartinger, deputy director of parks and public lands for the Wilderness Society. Removing the protections would be the first step you’d need to opening them back up to extractive uses like oil, timber and commercial fishing. Zinke promised to uphold the 1906 Antiquities Act, which gives the president power to create national monuments on public lands, but said he agrees with Trump that the law should not be be used to restrict historic uses like farming, grazing, ranching, timber harvesting, fishing or motorized recreation. Berryessa Snow Mountain, which sprawls across Napa, Solano, Yolo and four other counties in Northern California; Giant Sequoia, in the Sequoia National Forest in the southern Sierra; Cascade-Siskiyou, in southwestern Oregon and northwestern California; Carrizo Plain in the southern San Joaquin Valley; San Gabriel Mountains, northeast of Los Angeles; Santa Rosa and San Jacinto Mountains, west of the Coachella Valley in Riverside County; and two desert monuments that were pushed by Sen. Dianne Feinstein, Sand to Snow and Mojave Trails. Several California legislators and conservationists were confident that at least some of the state’s monuments would pass muster, even under an administration that has made clear that commercial interests should play a larger role in the government’s environmental decision-making. “The federal agencies have been very engaged and very responsive to our concerns,” said Amy Granat, managing director of the Off-Road Vehicle Association, which is working with officials on management plans at the desert monuments and Berryessa Snow Mountain that would permit off-road vehicles. David Lamfrom, California desert director for the National Parks Conservation Association, defended the desert monuments as crucial wildlife corridors that also preserve the last open stretch of historic Route 66. When the Trump administration reviews the California desert national monuments, they will find a community that strongly backs them and a business community that cares deeply about protecting them. The Antiquities Act “does not give the federal government unlimited power to lock up millions of acres of land and water, and it’s time we ended this abusive practice,” Trump said. The monument, named after a pair of buttes that rise above the Colorado Plateau, is the ancestral home of several American Indian tribes and features 100,000 archaeological sites, including ancestral Puebloan cliff dwellings. Legal experts say shrinking or revoking a monument would have to be done through an act of Congress, but some Republicans believe Trump can do it unilaterally and should be willing to go to court if necessary to win that right.