Established in 1911 by presidential proclamation, Devils Postpile National Monument protects and preserves the Devils Postpile formation, the 101-foot-high Rainbow Falls, and pristine mountain scenery. The formation is a rare sight in the geologic world and ranks as one of the world's finest examples of columnar basalt. Its columns tower up to 60 feet and display a striking symmetry. Devils Postpile National Monument lies at 7,560 feet above sea level just west of the Sierra Nevada crest and experiences typical summer weather in the Sierras, with possible afternoon thunderstorms in July and August, daytime temperatures from the mid-70s to the mid-80s degrees Fahrenheit, and evening temperatures dropping into the low 40s and even the low 30s in September and October.