The Dolomite Mine Ruins in Anza Borrego State Park date back to the 1930s. Once a Dolomite Marble and Magnesium Calcium Mine, this old structure is an intriguing place to explore. To the lay person, running your hands through the pure white fine powder that is still present to this day, brings to life the rich mineral deposits of ancient and metamorphic rocks overlain by marine sediments. 

Some five million years ago, much of this same landscape lay below sea level, underneath a shallow sea occupying the southeastern corner of California. Natural ebb and flow of sea levels.