Rainshadow
The Mojave desert, where I live, is in the Rain Shadow of the Sierra Nevada and Tehachapi Mountains to the northwest and the San Gabriel and San Bernardino Mountains to the south of us.
“Famous for its aridity, harsh conditions, and haunting landscapes, the Mojave Desert has lent an otherworldly backdrop to fiction from Star Trek to Fear and Loathing in Las Vegas. In fact, it encompasses Death Valley, the hottest place in North America. But to the countless animals and plants that call this desert home, it's far from a wasteland.
The Mojave encompasses approximately 25,000 square miles of California, southwestern Utah, southern Nevada, and northwestern Arizona. Both topographically and biologically, it has a little bit of everything: singing sand dunes, Joshua tree forests, wildflower fields, and a multitude of species — including more than 10 kinds of scorpions, several tarantulas, the federally listed desert tortoise, and more than 200 endemic plants.
While the Mojave's human population is sparse relative to other areas in the still-booming West, it's becoming increasingly urbanized as big cities like Los Angeles and Las Vegas spill out into the desert. With more people come highways, military bases, off-road vehicles, hunting, mining, grazing, and farming that destroy ecosystems and drain underground water reserves. The Mojave's wildness is slipping away fast.”
From The Center For Biological Diversity