The major desert located in the southwestern United States is the Sonoran Desert. This desert spans parts of Arizona, California, and Mexico, characterized by its diverse ecosystems and stunning landscapes, including the iconic saguaro cactus. The Sonoran Desert experiences extreme temperature fluctuations, with hot summers and mild winters. It is home to a variety of unique wildlife, plants, and cultural history tied to indigenous peoples like the Tohono O'odham. The desert is a significant area for outdoor recreation and ecological studies, showcasing the resilience of life in arid environments.