On April 26, 2017, President Trump ordered federal officials to review designations of onshore and marine national monuments made under the Antiquities Act of 1906. The Executive Order states that while

“[s]uch designations are a means of stewarding America’s natural resources, protecting America’s natural beauty, and preserving America’s historic places,” such designations, if they result from a lack of public outreach and proper coordination with state, tribal, and local officials, “may also create barriers to achieving energy independence, restrict public access to and use of Federal lands, burden State, tribal, and local governments, and otherwise curtail economic growth.”

The Order requires the Secretary of the Interior to conduct a review of all presidential designations or expansions of designations made under the Antiquities Act since January 1, 1996, where the designation (or designation after expansion) covered more than 100,000 acres, or where the Secretary determines that the designation or expansion was made without adequate public outreach and coordination with relevant stakeholders. The Secretary of the Interior is instructed to consult, as appropriate, with “the Secretary of Defense, the Secretary of Agriculture, the Secretary of Commerce, the Secretary of Energy, the Secretary of Homeland Security, and the heads of any other executive departments or agencies concerned with areas designated under the [Antiquities] Act” as well as governors of states affected by monument designations or other relevant officials of affected state, tribal, and local governments.

An interim report summarizing the findings of the Secretary of the Interior’s review is to be submitted to the White House within 45 days of the issuance of the Order, and a final report including recommendations for changes to the scope and size of those monuments is to be submitted to the President within 120 days.

Among the areas that will be under review are Bears Ears National Monument in Utah; the Grand Canyon-Parashant National Monument in Arizona; the Mojave Trails National Monument in California; and the Papahānaumokuākea Marine National Monument in the Pacific Ocean, the world's largest marine sanctuary.