Devils Postpile National Monument is a U.S. National Monument located near Mammoth Mountain in Eastern California. The monument protects Devils Postpile, an unusual rock formation of columnar basalt, “all closely and perfectly fitted together like a vast mosaic.” The monument encompasses and includes two main attractions: the Devils Postpile formation and Rainbow Falls, a waterfall on the Middle Fork of the San Joaquin River. In addition, the John Muir Trail and Pacific Crest Trail merge into one trail as they pass through the monument. Excluding a small developed area containing the monument headquarters, visitor center and a campground, the National Monument lies within the borders of the Ansel Adams Wilderness. History The monument was established in 1911 as "Devil Postpile National Monument," (no possessive) but is widely referred to as Devils Postpile National Monument, and has been officially styled as plural without the apostrophe since the 1930s. An alternate historic name was Devil’s Woodpile. “In every scenic freak the sheep-herder recognizes the work of his Satanic majesty. This formation is therefore known to local fame as the Devil’s Woodpile.” The monument was once part of Yosemite National Park, but discovery of gold in 1905 near Mammoth Lakes prompted a boundary change that left the Postpile on adjacent public land. Later, a proposal to build a hydroelectric dam called for blasting the Postpile into the river. Influential Californians, including John Muir, persuaded the federal government to stop the demolition and, in 1911, President William Howard Taft protected the area as a National Monument. Flora and fauna The elevation of the national monument is between , and the flora and fauna are typical of the western Sierra Nevada at these elevations. The monument area contains animals and plants such as black bears, pine martens, mule deer, coyotes, quaking aspen, black cottonwood, alder, and willows, Dark-eyed juncos and white-crowned sparrows are common in the summer. Native wildflowers include: Crimson columbine (Aquilegia formosa) Giant red Indian paintbrush (Castilleja miniata) Pine forest larkspur (Delphinium gracilentum) Sierra shooting star (Dodecatheon jeffreyi) Wandering fleabane (Erigeron peregrinus) Shortleaf hulsea (Hulsea brevifolia) Sierra tiger lily (Lilium parvum) Large-leaved lupine (Lupinus polyphyllus) Common yellow monkeyflower (Mimulus guttatus) Parish's yampah (Perideridia parishii) Sticky cinquefoil (Potentilla glandulosa) Ranger's buttons (Angelica capitellata) California corn lily (Veratrum californicum) Access The most common method for accessing Devils Postpile is via the mandatory shuttle bus operated by Eastern Sierra Transit Authority in the summer months, followed