Death Valley is currently building a rock collection of the park’s stratigraphy. The following list of geologic formations and corresponding ages represents what has been collected in the park and available for viewing at our curitorial facility. 41 formations are listed with a number correlating them to the original reference used to describe and locate them. Based on research, 61 formations are known to exist in the park. Those missing 20 formations have not yet been added to our Stratigraphy Collection. It should be noted that 3 formations have been given unofficial names: Warm Spring Granite, Skidoo Granite, and Strozzi’s Ranch Rhyolite.