At Pinnacles, the two main areas for spelunking are Bear Gulch, which I talked about in December, and the Balconies network of caves, which I’ll talk about today. All of the caves in Pinnacles are talus caves, which are formed over a period of time when rocks have fallen atop other rocks at the base of a cliff. In particular though, the caves at Pinnacles formed in the following manner: “…when steep, narrow canyons filled with a jumbled mass of boulders from the cliffs above. The canyons are the result of faults and fractures in the central area of volcanic rock. These shear fractures filled with gigantic toppled boulders are clear windows into the geologic wonder of the Monument.” (More information on the geology of Pinnacles here and here). In any case, both the Balconies cave and the Bear Gulch cave network provide a great spot to explore over 50 million years of geologic history over the course of a morning or afternoon.