I think all the North American deserts are rain-shadow deserts. By this I mean that in the direction of the prevailing winds, there are mountain ranges that parallel the coastline. Most of the moisture is squeezed out of the air by going over the mountains ⛰️ leaving large areas where the annual evaporation exceeds the annual rainfall.

This is exacerbated by the fact that the oceanic currents West of us are relatively cold. They don’t add as much moisture to the atmosphere as warm currents do.

There are several different deserts 🏜️, which can be divided along elevation, geology, precipitation, other climate measures, and by the biological organisms that live there. So for instance, the #High_Desert and #Intermediate_Desert ares of !SoCal have specific plants 🌱 and animals that live there. The #Low_Desert consist of multiple sub deserts with different climates and life forms. These deserts are generally located at lower elevations as well as being to the south of the other deserts. Most of the Low Deserts are subsets of the Sonoran Desert.