The Sonoran Desert's formation is largely attributed to volcanic activity that occurred millions of years ago, shaping the landscape.

The Sonoran Desert's unique topography and geological features were significantly shaped by volcanic activity. Over millions of years, volcanic eruptions produced vast lava flows and ash deposits, which altered the region's landscape and led to the formation of rugged mountains and valleys. These volcanic processes, combined with tectonic plate movements, created the desert's current structure. The Catalina Mountains and other prominent ranges within the desert are the result of volcanic activity, which helped shape the distinctive desert terrain we see today.