The Department of the Interior conducted an unprecedented federal review of 27 national monuments following an executive order on April 26, 2017, by President Donald Trump.
President Donald Trump issued proclamations on December 4, 2017, attempting to undo the following monuments, removing federal protections on roughly 2 million acres of land.
- Bears Ears, Utah
- Grand Staircase-Escalante, Utah
The Department of the Interior completed reviews of the following six national monuments and recommended no changes.
- Canyons of the Ancients, Colorado
- Craters of the Moon, Idaho
- Grand Canyon-Parashant, Arizona
- Hanford Reach, Washington
- Sand to Snow, California
- Upper Missouri River Breaks, Montana
The following 19 national monuments were under review, and their status is unclear.
- Basin and Range, Nevada
- Berryessa Snow Mountain, California
- Carrizo Plain, California
- Cascade Siskiyou, Oregon
- Giant Sequoia, California
- Gold Butte, Nevada
- Ironwood Forest, Arizona
- Katahdin Woods and Waters, Maine
- Marianas Trench, Northern Mariana Islands/Pacific Ocean
- Mojave Trails, California
- Northeast Canyons and Seamounts, Atlantic Ocean
- Organ Mountains-Desert Peaks, New Mexico
- Pacific Remote Islands, Pacific Ocean
- Papahanaumokuakea, Hawaii/Pacific Ocean
- Rio Grande del Norte, New Mexico
- Rose Atoll, American Samoa/Pacific Ocean
- San Gabriel Mountains, California
- Sonoran Desert, Arizona
- Vermilion Cliffs, Arizona