Devils Postpile National Monument is a

U.S. National Monument In the United States, a national monument is a protected area that can be created from any land owned or controlled by the federal government by proclamation of the President of the United States or an act of Congress. National monuments prot ...

located near

Mammoth Mountain Mammoth Mountain is a lava dome complex partially located within the town of Mammoth Lakes, California, in the Inyo National Forest of Madera and Mono Counties. It is home to a large ski area primarily on the Mono County side. Mammoth Mount ...

in Eastern California. The monument protects Devils Postpile, an unusual rock formation of

columnar basalt Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90% o ...

, “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 The San Joaquin River (; es, Río San Joaquín) is the longest river of Central California. The long river starts in the high Sierra Nevada, and flows through the rich agricultural region of the northern San Joaquin Valley before reaching Suis ...

. In addition, the

John Muir Trail The John Muir Trail (JMT) ( Paiute: Nüümü Poyo, ''N-ue-mue Poh-yo'') is a long-distance trail in the Sierra Nevada mountain range of California, passing through Yosemite, Kings Canyon and Sequoia National Parks. From the northern terminus a ...

and

Pacific Crest Trail The Pacific Crest Trail (PCT), officially designated as the Pacific Crest National Scenic Trail, is a long-distance hiking and equestrian trail closely aligned with the highest portion of the Cascade and Sierra Nevada mountain ranges, which lie ...

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 The Ansel Adams Wilderness is a wilderness area in the Sierra Nevada of California, United States. The wilderness spans ; 33.9% of the territory lies in the Inyo National Forest, 65.8% is in the Sierra National Forest, and the remaining 0.3% cove ...

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 Yosemite National Park ( ) is an American national park in California, surrounded on the southeast by Sierra National Forest and on the northwest by Stanislaus National Forest. The park is managed by the National Park Service and covers an ...

, but discovery of

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile ...

in 1905 near

Mammoth Lakes Mammoth Lakes is a town in Mono County, California, and is the county's only incorporated community. It is located immediately to the east of Mammoth Mountain, at an elevation of . As of the 2020 United States Census, the population was 7,191, r ...

prompted a boundary change that left the Postpile on adjacent

public land In all modern states, a portion of land is held by central or local governments. This is called public land, state land, or Crown land (Australia, and Canada). The system of tenure of public land, and the terminology used, varies between countrie ...

. Later, a proposal to build a

hydroelectric dam Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined a ...

called for blasting the Postpile into the river. Influential Californians, including

John Muir John Muir ( ; April 21, 1838December 24, 1914), also known as "John of the Mountains" and "Father of the National Parks", was an influential Scottish-American naturalist, author, environmental philosopher, botanist, zoologist, glaciologis ...

, persuaded the federal government to stop the demolition and, in 1911, President

William Howard Taft William Howard Taft (September 15, 1857March 8, 1930) was the 27th president of the United States (1909–1913) and the tenth chief justice of the United States (1921–1930), the only person to have held both offices. Taft was elected pr ...

protected the area as a

National Monument A national monument is a monument constructed in order to commemorate something of importance to national heritage, such as a country's founding, independence, war, or the life and death of a historical figure. The term may also refer to a spe ...

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 marten The European pine marten (''Martes martes''), also known as the pine marten, is a mustelid native to and widespread in most of Europe, Asia Minor, the Caucasus and parts of Iran, Iraq and Syria. It is listed as Least Concern on the IUCN Red List. ...

mule deer The mule deer (''Odocoileus hemionus'') is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. Two subspecies of mule deer are grouped into the black-tailed deer. Unlike the related whi ...

coyote The coyote (''Canis latrans'') is a species of canine native to North America. It is smaller than its close relative, the wolf, and slightly smaller than the closely related eastern wolf and red wolf. It fills much of the same ecological nich ...

s, quaking aspen,

black cottonwood ''Populus trichocarpa'', the black cottonwood, western balsam-poplar or California poplar, is a deciduous broadleaf tree species native to western North America. It is used for timber, and is notable as a model organism in plant biology. ...

alder Alders are trees comprising the genus ''Alnus'' in the birch family Betulaceae. The genus comprises about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few sp ...

, and

willow Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist so ...

s, Dark-eyed juncos and

white-crowned sparrow The white-crowned sparrow (''Zonotrichia leucophrys'') is a species of passerine bird native to North America. A medium-sized member of the New World sparrow family, this species is marked by a grey face and black and white streaking on the uppe ...

s are common in the summer. Native wildflowers include: *Crimson columbine (''

Aquilegia formosa ''Aquilegia formosa'', the crimson columbine, western columbine, or (ambiguously) "red columbine", is a common wildflower native to western North America, from Alaska to Baja California, and eastward to Montana and Wyoming. Description ''Aquile ...

'') *Giant red Indian paintbrush (''

Castilleja miniata ''Castilleja miniata'' is a species of Indian paintbrush known by the common name giant red Indian paintbrush. It is native to western North America from Alaska to Ontario to California to New Mexico, where it grows usually in moist places in a ...

'') *Pine forest larkspur (''

Delphinium gracilentum ''Delphinium gracilentum'' is a species of larkspur known by the common name pine forest larkspur. It is endemic to California, where it grows throughout the Sierra Nevada. This wildflower is usually around half a meter in maximum height, with ...

'') *Sierra shooting star ('' Dodecatheon jeffreyi'') *Wandering fleabane ('' Erigeron peregrinus'') *Shortleaf hulsea ('' Hulsea brevifolia'') *Sierra tiger lily ('' Lilium parvum'') *Large-leaved lupine (''

Lupinus polyphyllus ''Lupinus polyphyllus'', the large-leaved lupine, big-leaved lupine, many-leaved lupine, blue-pod lupine, or, primarily in cultivation, garden lupin, is a species of lupine (lupin) native to western North America from southern Alaska and British ...

'') *Common yellow monkeyflower (''

Mimulus guttatus ''Erythranthe guttata'', with the common names seep monkeyflower and common yellow monkeyflower, is a yellow bee-pollinated annual or perennial plant. It was formerly known as ''Mimulus guttatus''. ''Erythranthe guttata'' is a model organism fo ...

'') *Parish's yampah (''

Perideridia parishii ''Perideridia parishii'' is a species of flowering plant in the family Apiaceae known by the common name Parish's yampah. It is native to mountainous regions of the southwestern United States, where it grows in forests and other habitat. It is a ...

'') *Sticky cinquefoil ('' Potentilla glandulosa'') *Ranger's buttons (''

Angelica capitellata ''Angelica capitellata'', synonym ''Sphenosciadium capitellatum'', is a species of flowering plant in the family Apiaceae. When treated as ''Sphenosciadium capitellatum'', it was the only species in the monotypic genus ''Sphenosciadium''. It is ...

'') *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 by a 1/4 mile walk. The shuttle route begins at Mammoth Mountain Ski Area's Adventure Center and makes several stops throughout the valley and begins operating when the Reds Meadow Road opens in the summer, and continues through Labor Day weekend. Devils Postpile is also accessible on foot from Mammoth Lakes by hiking over Mammoth Pass and into the Reds Meadow Valley. During the winter months, there are no services available, but adventurers can visit the site via cross-country ski or snowshoe.

Devils Postpile

The name "Devils Postpile" refers to a dark cliff of

Radiometric dating Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares ...

indicates the formation was created by a lava flow at some time less than 100,000 years ago. The source of the lava is thought to have been somewhere near Upper Soda Springs

campground A campsite, also known as a campground or camping pitch, is a place used for overnight stay in an outdoor area. In British English, a ''campsite'' is an area, usually divided into a number of pitches, where people can camp overnight using te ...

at the north end of Pumice Flat on the floor of the Middle Fork of the

, from where it flowed to the site of the Postpile. Estimates of the formation's thickness range from to . The lava that now makes up the Postpile was near the bottom of this mass. Because of its great thickness, much of the mass of pooled lava cooled slowly and evenly, which is why the columns are so long and so symmetrical. Columnar jointing occurs when certain types of lava contract while cooling. A

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such a ...

later removed much of this mass of rock and left a polished surface on top of the columns with very noticeable

glacial striations Glacial striations or striae are scratches or gouges cut into bedrock by glacial abrasion. These scratches and gouges were first recognized as the result of a moving glacier in the late 18th century when Swiss alpinists first associated them w ...

and

glacial polish Glacial polish is a characteristic of rock surfaces where glaciers have passed over bedrock, typically granite or other hard igneous or metamorphic rock. Moving ice will carry pebbles and sand grains removed from upper levels which in turn grind ...

. The Postpile's columns average in diameter (“The columns vary in size from ten to 30 inches in diameter.”), the largest being , and many are up to long. Together they look like tall posts stacked in a pile, hence the feature's name. If the lava had cooled perfectly evenly, all of the columns would be expected to be hexagonal, but some of the columns have different polygonal cross-sections due to variations in cooling. A survey of 400 of the Postpile's columns found that 44.5% were 6-sided, 37.5% 5-sided, 9.5% 4-sided, 8.0% 7-sided, and 0.5% 3-sided. Compared with other examples of columnar jointing, the Postpile has more hexagonal columns. Another feature that places the Postpile in a special category is the lack of horizontal jointing.

Similar structures

Although the basaltic columns are impressive, they are not unique. Basalt columns are a common volcanic feature, and they occur on many scales (faster cooling produces smaller columns). Other notable sites include Svartifoss in Vatnajökull National Park in

Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its ...

Giant's Causeway The Giant's Causeway is an area of about 40,000 interlocking basalt columns, the result of an ancient volcanic fissure eruption. It is located in County Antrim on the north coast of Northern Ireland, about three miles (5 km) northeast of ...

Northern Ireland Northern Ireland ( ga, Tuaisceart Éireann ; sco, label=Ulster Scots dialect, Ulster-Scots, Norlin Airlann) is a part of the United Kingdom, situated in the north-east of the island of Ireland, that is #Descriptions, variously described as ...

Fingal's Cave Fingal's Cave is a sea cave on the uninhabited island of Staffa, in the Inner Hebrides of Scotland, known for its natural acoustics. The National Trust for Scotland owns the cave as part of a national nature reserve. It became known as Finga ...

in Scotland, Titan's Piazza of the Mount Holyoke Range in

Massachusetts Massachusetts (Massachusett: ''Muhsachuweesut Massachusett_writing_systems.html" ;"title="nowiki/> məhswatʃəwiːsət.html" ;"title="Massachusett writing systems">məhswatʃəwiːsət">Massachusett writing systems">məhswatʃəwiːsət'' En ...

, the

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, the Cyclopean Isles near

Sicily (man) it, Siciliana (woman) , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = Ethnicity , demographics1_footnotes = , demographi ...

Sheepeater Cliff The Sheepeater Cliffs are a series of exposed cliffs made up of columnar basalt in Yellowstone National Park in the United States. The lava was deposited about 500,000 years ago during one of the periodic basaltic floods in Yellowstone Caldera, ...

Yellowstone National Park Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowst ...

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to t ...

, Basaltic Prisms of Santa María Regla in Huasca de Ocampo,

Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...

, the Organ Pipes formation on Mount Cargill in

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...

Gilbert Hill Gilbert Hill is a monolith column of black basalt rock at Andheri, in Mumbai, India. The rock has a sheer vertical face and was formed when molten lava was squeezed out of the Earth's clefts during the Mesozoic Era about 66 million years ago. ...

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and the Column Cape (Russian: ''Mis Stolbchaty'') on

Kunashir Island , other_names = kz, Kün Ashyr; ja, 国後島 , location = Sea of Okhotsk , locator_map = File:Kurily Kunashir.svg , coordinates = , archipelago = Kuril Islands , total_islands = , major_islands = , area = , length = , width = fr ...

, the southernmost of the

Kuril Islands The Kuril Islands or Kurile Islands (; rus, Кури́льские острова́, r=Kuril'skiye ostrova, p=kʊˈrʲilʲskʲɪjə ɐstrɐˈva; Japanese language, Japanese: or ) are a volcanic archipelago currently administered as part of Sakh ...

, Cerro Colorado and Mar Brava (Ancud) in

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...

. Columnar basalt can also be seen in a high desert dry river falls area just north of

Lajitas, Texas Lajitas is an unincorporated community in Brewster County, Texas, United States, near the Big Bend National Park. According to the Handbook of Texas, the community had a population of 75 in 2010. History The settlement is named after the Boquillas ...

. The much more massive Devils Tower National Monument in

is superficially similar but consists of a

phonolite Phonolite is an uncommon extrusive rock, of intermediate chemical composition between felsic and mafic, with texture ranging from aphanitic (fine-grained) to porphyritic (mixed fine- and coarse-grained). Phonolite is a variation of the igneous ...

porphyry, formed by the

intrusion In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...

igneous rock Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma o ...

References

Bibliography

* ''Roadside Geology of Northern and Central California'', Alt, Hyndman (Mountain Press Publishing Company, Missoula; 2000)

External links

NPS Devils Postpile National Monument website

Geology field notes
* {{authority control National Park Service National Monuments in California Parks in Madera County, California Protected areas of the Sierra Nevada (United States) Columnar basalts Rock formations of California Volcanic plugs of California Landforms of Madera County, California Protected areas established in 1911 1911 establishments in California