Map showing high-purity quartzite in California, Nevada, Utah, Idaho, and Montana

Unusually pure quartzite of Ordovician age crops out in hundreds of places from Owens River, California to southwestern Montana.  It constitutes a single lithologic type that is called the Kinnikinic Quartzite in central Idaho, the Swan Peak Quartzite in southeastern Idaho and adjacent parts of Utah, and the Eureka Quartizite in western Utah, Nevada, and southern California.