New California National Monuments


The desert landscapes of California are iconic — rugged, awe-inspiring landscapes with sweeping vistas mostly unblemished by the hand of humans. They are also habitat for iconic plants and animals including the desert tortoise, bighorn sheep, eagles and stunning spring and fall wildflower shows. 

Special landscapes have been earmarked for decades for additional protection because of the unique features they harbor.  The Center has advocated vigorously for decades for the designation of these areas as three new national monuments.

In February 2016 we saw victory when President Barack Obama announced those very designations, protecting 1.8 million acres of public lands in perpetuity as national monuments. National monument status helps to assure that these irreplaceable landscapes will remain in their current wild and untamed state for future generations to experience and enjoy.

However, on April 26, 2017, President Trump signed Executive Order 13792 directing the Interior Department to review every monument designated since 1996 that is larger than 100,000 acres, which includes both Mojave Trails and Sand to Snow national monuments. Now both of these monuments may be shrunk in size or eliminated altogether. Please take action here.

Details on the three new national monuments:


Mojave Trails National Monument preserves 1.6 million acres of diverse and striking desert lands that link Joshua Tree National Park and Mojave National Preserve. Named for the most pristine stretch of historic Route 66, with wide-open desert vistas, the lands in the national monument are habitat for threatened desert tortoises and iconic desert bighorn sheep. The monument includes numerous important destination spots, like

  • the Amboy Crater, already designated as a “national natural landmark”;
  • the Pisgah Lava Flow, the most researched area in North America when it comes to the effects of volcanism on biological evolution;
  • Sleeping Beauty Valley — the last intact valley of West Mojave plant associations, on the eastern edge of the west Mojave desert;
  • Afton Canyon, where the Mojave River flows year-round, forming a desert oasis amid colorful canyon walls;
  • the Cady Mountains, one of the best ranges in the Mojave to see bighorn sheep;
  • the Marble Mountains Fossil Beds — the site of 550-million-year-old fossils of trilobites, which were among the first animals on Earth with eyes and skeletons;
  • numerous unique sand-dune systems, including the Cadiz dunes; and
  • an important portion of California's largest cactus garden.

Not only does this monument connect two national park units, but it also links 13 wilderness areas into a larger matrix of conserved public lands. Only two hours away from the homes of 16 million people in urbanized Southern California, Mojave Trails National Monument provides a refuge for campers and explorers, as well as an opportunity to see bighorn sheep, desert tortoises, fringe-toed lizards and other rare animals — plus riotous displays of spring and fall wildflowers.

National monument status protects the existing uses of these lands for outdoor enjoyment and ensures that key wildlife connections will remain between national parks and wilderness areas. 


Sand to Snow National Monument rises from the Sonoran desert floor up to Southern California's tallest mountain: Mount San Gorgonio, at 11,503 feet. This monument's 154,000 acres contains a rich tapestry of landscapes and wildlife habitats, including alpine peaks, conifer forests, pinyon forests, Joshua tree woodlands, alpine streams, rivers and desert oases, Sonoran and Mojave desert lands, and coastal chaparral. The monument also includes 25 miles of the Pacific Crest Trail. The headwaters of Southern California's longest and steepest river, the Santa Ana River, occur on the upper slopes of the monument, as do the headwaters of the Whitewater River.   

The convergence of so many landscape influences — montane, desert and coastal — make this area a living laboratory for evolution and a hotspot for biodiversity.

A mere 1.5 hours away from Southern California cities teeming with people living far from the wild, this monument — like Mojave Trails National Monument —readily provides a diversity of outdoor enjoyment throughout the seasons, from world-class hiking to backpacking to wildlife and bird watching.



Castle Mountains National Monument  brings into conservation a missing piece in the northern part of the Mojave National Preserve. Castle Mountains were originally carved out of Mojave National Preserve when it was established because of a large operational gold mine — but this mine was been reclaimed since the preserve's formation, allowing the Castle Mountains to take their correct place as a rugged addition (spanning 20,900 acres) to the conserved landscape.

Castle Mountain National Monument is home to Joshua tree forests, washes filled with willows, unique desert grasslands not typically found in the Mojave Desert — and of course, its namesake Castle Mountains, where herds of desert bighorn sheep roam.

This remote part of California's Mojave Desert is still only four hours away from urban Southern California and only 1.5 hours away from the half-million people in Las Vegas, Nevada. The establishment of Castle Mountains National Monument makes Mojave National Preserve whole and provides access for millions of people to rugged mountains, desert grasslands and unparalleled wildlife viewing.



Mount San Gorgonio photo courtesy Flickr Commons/Amy Fry