President Obama has already earned a reputation as a presidential protector of lands, designating everything from an ill-fated mammoth nursery to a park memorializing Harriet Tubman as national monuments. Now, he’s done it again. The New York Times’ Mark Landler writes that the president will nearly double his already-protected public lands with the designation of 1.8 million acres of the California desert as three national monuments.

In a release, the White House notes that the new designations will link together existing protected areas like Joshua Tree National Park and Mojave National Preserve with wilderness areas designated by Congress, “permanently protecting key wildlife corridors and providing plants and animals with the space and elevation range that they will need in order to adapt to the impacts of climate change.”

Landler reports that the designation was the result of a request by Senator Dianne Feinstein (D-CA) to protect lands after legislation to do so failed. As Louis Sahagun notes for the Los Angeles Times, the lands had become a legal battleground between environmental groups, mining interests and ranchers.

With the announcement, Obama’s land protection legacy rises to over 265 million acres on land and at sea—the biggest of any president. Here’s what you need to know about the three new monuments:

Mojave Trails National Monument

This is the largest of the newly protected areas and spans 1.6 million acres, over 350,000 of which were already protected. The area includes ancient Native American trading routes, a long stretch of Route 66, and World War II training camps. Natural highlights include the Pisgah Crater lava flows, Marble Mountains Fossil Beds, and the Amboy Crater.

Sand to Snow National Monument

This new monument spans 154,000 acres, over 100,000 of which were already protected. The area is known for its diverse terrain, habitat linkages, and thousands of ancient petroglyphs.

Castle Mountains National Monument

This new monument spans 20,920 acres in what KCET’s Chris Clarke calls “a botanical wonderland.” The area spans a mountain range with diverse desert flora and spectacular views.