The Caverns of Sonora are consistently ranked among the most spectacular caves in the world. What they lack in size is made up for by the sheer abundance and variety of their calcite formations. Among them, visitors will experience cave bacon, which is a type of flowstone that resembles the popular breakfast food, soda straw stalactites, and cave popcorn. The most famous of the cave’s formations is the Butterfly, which consists of two fishtail helictite growths that share the same attachment point. This formation is the only one of its kind in the world.
History of Sonora Caverns
According to the Caverns of Sonora park website, the cave formed out of limestone that is estimated to be about 100 million years old. Approximately 1.5-5 million years ago, the caverns formed as underground gases escaping through an ancient fault mixed with groundwater in the area. The resulting acidic water dissolved the surrounding limestone until the water drained from the cave about 1-3 million years ago. Since that time, the action of dripping water has formed some of the purest and most complex calcite formations ever discovered. The Caverns of Sonora are also one of the most active caves in the world. Upwards of 95% of their formations are still growing.
The cave was originally discovered on the Mayfield family ranch at the turn of the twentieth century. In the mid-1950s, speleologists discovered the full extent of the caverns, at which point preservation efforts began in earnest. The Caverns of Sonora park opened in 1960, and in 1966 was designated a National Natural Landmark by the United States Department of the Interior.
