No single region of North America is more biodiverse or ecologically spectacular than Southern California. This is the only place on the continent that spans arid deserts and lush forests, snow-covered peaks and the coast — creating habitat for an extraordinary number of species found nowhere else on Earth.
But Southern California is also one of the fastest-growing regions in the country, currently home to approximately two-thirds of the 38 million people living in the state. In Riverside County alone, the population increased by more than 42 percent between 2000 and 2013 — reaching 2.3 million people — and building permits doubled within this time.
The enormous  value of Southern California's wildlands, paired with the region's enormous hunger  for human-supporting infrastructure, makes it one of the country's most  difficult and important regions for  properly managing wild places. Urban wildlands in particular are critical,  those areas in which humans' living space and wild species' living space meet.  Our job in such places, especially in regions as heavily populated as Southern  California, is to ensure that people's quality of life is supported by an  abundance of biodiversity — while humans likewise support, instead of threaten,  that abundance.
        
At the Center we believe that the quality of life for Southern California's many residents is intricately linked to the protection of wild open spaces and the other species that also call the region home.
LOS ANGELES COUNTY
          
          Newhall Ranch
This massive housing development will impair important riparian habitat of the  last free-flowing river system in the Los Angeles basin: the Santa Ana River.  It will directly impact the least  Bell's vireo, unarmored  threespine stickleback and San Fernando spineflower. The Center won an  important California  Environmental Quality Act victory against the Department of Fish and  Wildlife for issuing a permit to channelize, fill, and otherwise severely alter  the Santa Clara River and its tributaries and destroy this essential habitat. We're  engaged in several other active lawsuits to stop the project before any damage  is done.
Tejon Ranch
For more than a decade the Center has been fighting to protect Tejon Ranch —  one of California's most magnificent landscapes, critical habitat for the California  condor, and home to dozens of other threatened and endangered species. Wall  Street real estate speculators have proposed three massive projects on Tejon  that would constitute the largest real estate development project in California  history. Together they could spell doom for the California condor in the wild,  pave a swath of destructive sprawl from Los Angeles to Bakersfield, and drive a  stake through the heart of the irreplaceable Tehachapi ecosystem.
RIVERSIDE COUNTY
World Logistics Center
          This 41.6 million square foot warehouse project will substantially affect  Moreno Valley's air quality, human health, as well as the Stephens' kangaroo  rat and other threatened species.  The Center submitted comments  on the project and will continue to watchdog and fight the project to prevent  its harmful impacts from being realized.
          
          Santa Ana Sucker  critical habitat
          The Center successfully sued the U.S. Fish and Wildlife Service to designate  critical habitat for the endangered Santa Ana sucker, and we've subsequently  defended that protected habitat against lawsuits by local water interests that  are essentially designed to gut such designations and protections. As long as  the Santa Ana River appears to be a “path of least resistance” to the sprawl  development industry, the sucker and other endangered and threatened species  will still be at risk. But the Center will be there, working to protect them  and to ensure that the laws in place continue to be followed.
SAN BERNARDINO COUNTY
Cadiz Water Project
        A private water reseller has proposed to pump groundwater from the Mojave  Desert and pipe it hundreds of miles from San Bernardino County to Orange  County to fuel speculative development sprawl. The project threatens to dry up  the area's few natural springs and completely de-water seasonal lake beds,  stealing habitat from species — including the desert  tortoise, desert bighorn sheep, Mojave  fringe-toed lizard and desert  kit fox. The Center and our allies are fighting this terrible project on  all fronts, including by filing a major lawsuit in 2012. 
SAN DIEGO COUNTY
Fanita Ranch
          The Center went to court repeatedly — and successfully — to stop this massive  sprawl housing project, which would have negatively affected vernal pool  habitat, water supply and traffic, besides creating increased fire hazards.  Fanita Ranch is currently on hold, pending further environmental review and a  likely redesign.
The Castlerock Development
        Settling our lawsuit, developer Pardee  Homes agreed to revise the project to protect Quail Canyon Creek and to make  additional land available for public open space and wildlife habitat. “With  Pardee's agreement to avoid the most sensitive parts of the Castlerock site and  to expand regional open space, this settlement will benefit the public,  wildlife and habitat,” said John Buse, a senior attorney with the Center.
VENTURA COUNTY
Presidential  Substation Project
          Southern California Edison has proposed to build a new electrical substation  with high-tension power lines in a residential area — and in protected critical habitat for the California  gnatcatcher. The corporation continues to push the wasteful and destructive  plan, while ignoring far superior alternatives. The Center has been working  with local allies to force SC Edison to consider proposed alternatives that  would protect gnatcatcher habitat and open spaces, and to reroute any  high-tension lines away from area homes.