Devils Postpile National Monument is located near Mammoth Mountain in extreme northeastern Madera County in eastern California. It was created in 1911 as Devil Postpile National Monument,[3] and has long been widely referred to as Devil's Postpile National Monument;[4] but it has been officially styled as plural without the apostrophe since the 1930s. The national monument protects Devil's Postpile, an unusual formation of columnar basalt.
