President Barack Obama has designated three new national monuments  -- all of them in the California desert -- through the Antiquities Act. The National Park Service will administer one of them, Castle Mountains National Monument (MN82), making it eligible to become the newest new National Parks on the Air (NPOTA) unit. The nearly 21,000 acre tract became the 484th NPOTA unit as of February 12.

Castle Mountains National Monument is surrounded on three sides by another NPOTA unit — the Mojave National Preserve (PV13).

“It connects water flow and wildlife corridors of the Preserve, and completes the boundary of the Preserve along the California-Nevada border,” the White House said. The other national monuments created were Sand to Snow National Monument, and Mojave Trails National Monument. The three new national monuments comprise approximately 1.8 million acres.