Across Arizona and much of the Southwest, the saguaro cactus is admired for the way it thrives in the desert. Saguaros are the largest cactus in the United States, and can only be found in the Sonoran Desert. These iconic green giants can grow up to 40 feet tall and live for more than 150 years. They are well-equipped to survive droughts by absorbing and storing rainwater. Saguaros can grow several arms, sometimes curled but often raised, in a never-ending manner of greeting residents and visitors.