Last year, President Joe Biden announced that he intended to create a national monument in southeast Nevada, and last week he fulfilled that pledge.

Avi Kwa Ame National Monument is sacred to a dozen tribes, including several Yuman-speaking groups that live along the Colorado River.

The 506,814-acre site, which is also known as Spirit Mountain, "is considered to be among the most sacred places on Earth by the Mojave, Chemehuevi, and some southern Paiute people," according to the Bureau of Land Management.

Conservationists say the monument will connect ecosystems in the California desert to the Colorado Plateau and help offset climate change. The new monument "creates one of the largest contiguous areas of protected wildlife habitat in the United States, tying together the protected lands of the Mojave Desert in California to the southwest with the Lake Mead National Recreation Area," according to the White House. 

The protected area also contains several native species — such as desert bighorn sheep, Gila monsters, desert tortoises and Arizona toads — and an ancient Joshua forest which is home to Nevada's largest Joshua trees.