Devils Postpile National Monument

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The Devils Postpile National Monument
Devils Postpile National Monument near Mammoth Lakes.jpg
Basalt columns of Devils Postpile
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Location Madera County, California, United States
Nearest city Mammoth Lakes, CA
Coordinates 37°37′28″N119°5′4″W / 37.62444°N 119.08444°W / 37.62444; -119.08444 Coordinates: 37°37′28″N119°5′4″W / 37.62444°N 119.08444°W / 37.62444; -119.08444
Area798 acres (323 ha) [1]
CreatedJuly 6, 1911 (1911-July-06)
Visitors109,571(in 2017) [2]
Governing body National Park Service
Website Devils Postpile National Monument

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. It encompasses 798 acres (323 ha) 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. [3] 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. [4]



Rainbow Falls at Devils Postpile National Monument Rainbow Falls Devils Postpile.jpg
Rainbow Falls at Devils Postpile National Monument

The monument was established in 1911 as "Devil Postpile National Monument," [5] but is widely referred to as Devils Postpile National Monument, [6] and has been officially styled as plural without the apostrophe since the 1930s. 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. [7] 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. [7]

Flora and fauna

The flora and fauna at Devils Postpile are typical of the Sierra Nevada. [8] The monument area contains animals and plants such as black bears, pine martens, mule deer, coyotes, [9] quaking aspen, black cottonwood, alder, and willows, [10] as well as many wildflowers, such as cinquefoil and alpine shooting star. [11] Dark-eyed juncos and white-crowned sparrows are common in the summer. [11]


The most common method for accessing Devils Postpile is via the mandatory shuttle bus operated by Eastern Sierra Transit Authority in the summer months, [12] 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. [13]

Devils Postpile

The tops of the postpile columns are accessible to visitors. The shapes of the column cross sections are seen clearly here. California, Devils Postpile National Monument, columns top.jpg
The tops of the postpile columns are accessible to visitors. The shapes of the column cross sections are seen clearly here.

The name "Devils Postpile" refers to a dark cliff of columnar basalt. Radiometric dating indicates the formation was created by a lava flow at some time less than 100,000 years ago. [14] The source of the lava is thought to have been somewhere near Upper Soda Springs campground at the north end of Pumice Flat on the floor of the Middle Fork of the San Joaquin River, from where it flowed to the site of the Postpile. Estimates of the formation's thickness range from 400 feet (120 m) to 600 feet (180 m). The lava that now makes up the Postpile was near the bottom of this mass. [14]

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 later removed much of this mass of rock and left a polished surface on top of the columns with very noticeable glacial striations and glacial polish. [14]

The Postpile's columns average 2 feet (0.61 m) in diameter, the largest being 3.5 feet (1.1 m), and many are up to 60 feet (18 m) 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. [14] 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

Top of columnar basalt shows polygonal shapes Devils Postpile pentagon.jpg
Top of columnar basalt shows polygonal shapes

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, Giant's Causeway in Northern Ireland, Fingal's Cave in Scotland, Titan's Piazza of the Mount Holyoke Range in Massachusetts, the Garni Gorge in Armenia, the Cyclopean Isles near Sicily, Sheepeater Cliff at Yellowstone National Park in Wyoming, Basaltic Prisms of Santa María Regla in Huasca de Ocampo, Mexico, the "Organ Pipes" formation on Mount Cargill in New Zealand, Gilbert Hill in Mumbai, Organ Pipes National Park in Australia and the "Column Cape" (Russian: Mis Stolbchaty) on Kunashir Island, the southernmost of the Kuril Islands, Cerro Colorado and Mar Brava (Ancud) in Chile,. Columnar basalt can also be seen in a high desert dry river falls area just north of Lajitas, Texas. The much more massive Devils Tower National Monument in Wyoming is superficially similar but consists of a phonolite porphyry, formed by the intrusion of igneous rock. [15]

See also

Related Research Articles

John Muir Trail Trail in the Sierra Nevada mountains of California

The John Muir Trail (JMT) 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 at Happy Isles in Yosemite Valley and the southern terminus located on the summit of Mount Whitney, the trail's length is 213.7 miles (343.9 km), with a total elevation gain of approximately 47,000 feet (14,000 m). For almost all of its length, the trail is in the High Sierra backcountry and wilderness areas. For about 160 miles (260 km), the trail follows the same footpath as the longer Pacific Crest Trail. It is named after John Muir, a naturalist.

Ansel Adams Wilderness Protected wilderness area in California, United States

The Ansel Adams Wilderness is a wilderness area in the Sierra Nevada of California, United States. The wilderness spans 231,533 acres (93,698 ha); 33.9% of the territory lies in the Inyo National Forest, 65.8% is in the Sierra National Forest, and the remaining 0.3% covers nearly all of Devils Postpile National Monument. Yosemite National Park lies to the north and northwest, while the John Muir Wilderness lies to the south.

Lava Beds National Monument

Lava Beds National Monument is located in northeastern California, in Siskiyou and Modoc counties. The monument lies on the northeastern flank of Medicine Lake Volcano and has the largest total area covered by a volcano in the Cascade Range.

Devils Tower United States National Monument near Moorcroft, Wyoming

Devils Tower is a butte, possibly laccolithic, composed of igneous rock in the Bear Lodge Ranger District of the Black Hills, near Hulett and Sundance in Crook County, northeastern Wyoming, above the Belle Fourche River. It rises 1,267 feet above the Belle Fourche River, standing 867 feet from summit to base. The summit is 5,112 feet above sea level.

Lassen Volcanic National Park National park in California, United States

Lassen Volcanic National Park is an American national park in northeastern California. The dominant feature of the park is Lassen Peak, the largest plug dome volcano in the world and the southernmost volcano in the Cascade Range. Lassen Volcanic National Park is one of the few areas in the world where all four types of volcano can be found—plug dome, shield, cinder cone, and stratovolcano.

John Muir Wilderness Protected area in the Sierra Nevada of California, US

The John Muir Wilderness is a wilderness area that extends along the crest of the Sierra Nevada of California for 90 miles (140 km), in the Inyo and Sierra National Forests. Established in 1964 by the Wilderness Act and named for naturalist John Muir, it encompasses 652,793 acres (2,641.76 km2). The wilderness lies along the eastern escarpment of the Sierra from near Mammoth Lakes and Devils Postpile National Monument in the north, to Cottonwood Pass near Mount Whitney in the south. The wilderness area also spans the Sierra crest north of Kings Canyon National Park, and extends on the west side of the park down to the Monarch Wilderness.


Svartifoss is a waterfall in Skaftafell in Vatnajökull National Park in Iceland, and is one of the most popular sights in the park. It is surrounded by dark lava columns, which gave rise to its name. Other well-known columnar jointing formations are seen at the Giant's Causeway in Northern Ireland, Devil's Tower in Wyoming, United States and on the island of Staffa in Scotland. There are also similar formations throughout Iceland, including a small cave on the beach of Reynisdrangar.

Gilbert Hill

Gilbert Hill is a 200 ft (61 m) 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. During that era, molten lava had spread around most of the Indian states of Maharashtra, Gujarat and Madhya Pradesh, covering an area of 50,000 square kilometres (19,000 sq mi). The volcanic eruptions were also responsible for the destruction of plant and animal life during that era. According to experts, this rare geological phenomenon was the remnant of a ridge and had clusters of vertical columns in nearby Jogeshwari which were quarried off two decades ago. These vertical columns are similar to the Devils Tower National Monument in Wyoming, and the Devils Postpile National Monument in eastern California, USA. Gilbert Hill was declared a National Park in 1952 by the Central Government under the Forest Act. In 2007, after years of lobbying by geologists, the hill was declared a Grade II heritage structure by the Municipal Corporation of Greater Mumbai (MCGM), and all quarrying and other activities around the monument were prohibited. Over the period of time, Gilbert Hill has faced severe erosion problems too.

Inyo National Forest

Inyo National Forest is a United States National Forest covering parts of the eastern Sierra Nevada of California and the White Mountains of California and Nevada. The forest hosts several superlatives, including Mount Whitney, the highest point in the contiguous United States; Boundary Peak, highest point in Nevada; and the Ancient Bristlecone Pine Forest that protects the oldest trees in the world. The forest, encompassing much of Owens Valley, was established by Theodore Roosevelt as a way of sectioning off land to accommodate the Los Angeles Aqueduct project in 1907, making the Inyo National Forest one of the least wooded forests in the United States' system.

Little Devils Postpile

Little Devils Postpile is a columnar basalt rock formation in the Sierra Nevada, located within Yosemite National Park and eastern Tuolumne County, California.

Trap rock Dark-colored, fine-grained, non-granitic intrusive or extrusive igneous rock

Trap rock, also known as either trapp or trap, is any dark-colored, fine-grained, non-granitic intrusive or extrusive igneous rock. Types of trap rock include basalt, peridotite, diabase, and gabbro. Trapp (trap) is also used to refer to flood (plateau) basalts, e.g. the Deccan Traps and Siberian Traps. The erosion of trap rock created by the stacking of successive lava flows often created a distinct stairstep landscape from which the term trap was derived from the Swedish word trappa, which means "stairway".

Thousand Island Lake

Thousand Island Lake is a large alpine lake in the Sierra Nevada, within the Ansel Adams Wilderness in eastern Madera County, California.

Columnar jointing Polygonal stone columns

Columnar jointing is a geological structure where sets of intersecting closely spaced fractures, referred to as joints, result in the formation of a regular array of polygonal prisms, or columns. Columnar jointing occurs in many types of igneous rocks and forms as the rock cools and contracts. Columnar jointing can occur in cooling lava flows and ashflow tuffs (ignimbrites), as well as in some shallow intrusions. Columnar jointing also occurs rarely in sedimentary rocks if they have been heated by nearby hot magma.

Minaret Summit

Minaret Summit is a mountain pass on Highway 203 in the central Sierra Nevada. The pass, lying on the Madera-Mono County border, is within the Mammoth Ranger District of the Inyo National Forest and located near Devils Postpile National Monument, Mammoth Lakes, and Mammoth Mountain. The elevation of the pass is about 9,265 ft (2,824 m). Highway 203 ends at Minaret Summit. The road continues, now called Reds Meadow Road, until its dead end at the Reds Meadow Pack Station near the Rainbow Falls trailhead.

Hughes Mountain

Hughes Mountain and the Hughes Mountain State Natural Area are located in southern Washington County, Missouri just south of the Big River and Highway M on Cedar Creek Road in the St. Francois Mountains range of The Ozarks. The mountain reaches an elevation of just over 1,200 feet, rising 430 feet above the Big River. The Hughes Mountain Natural Area of the Missouri Department of Conservation encompasses 462 acres (1.87 km2) of the mountain, including the rhyolite glade at its top.

Rainbow Falls (California)

Rainbow Falls is the highest waterfall on the Middle Fork of the San Joaquin River, in the eastern Sierra Nevada mountains of California, in the United States. Plunging 101 feet (31 m) to the turbulent water below, the falls are named for the rainbows that appear in their mist on sunny summer days. Rainbow Falls is located within the boundaries of Devils Postpile National Monument.

Lions Fire

The Lions Fire was a wildfire in the Ansel Adams Wilderness in Inyo National Forest and the Sierra National Forest in California in the United States. The fire was started by a lightning strike and first reported on June 11, 2018. The fire impacted recreational activities in both national forests, as well as access to Devils Postpile National Monument. The Lions Fire burned a total of 13,347 acres (54 km2), before burning out on October 1.

The protected areas of the Sierra Nevada, a major mountain range located in the U.S. states of California and Nevada, are numerous and highly diverse. Like the mountain range itself, these areas span hundreds of miles along the length of the range, and over 14,000 feet of elevation from the lowest foothills to the summit of Mount Whitney.


  1. "Listing of acreage as of December 31, 2013" (PDF). Land Resource Division, National Park Service. Retrieved 2014-03-16.
  2. "NPS Annual Recreation Visits Report". National Park Service. Retrieved 2018-03-29.
  3. "Visitor Guide to Devils Postpile and the Reds Meadow Valley, 2011-2012" (PDF). National Forest Service/National Park Service. p. 10. Retrieved 2012-03-23.
  4. "Ansel Adams Wilderness acreage breakdown". Archived from the original on 2012-07-01.
  5. States, United (1911). "A Proclamation". Statutes of the United States of America.
  6. "Devil Postpile National Monument". Sierra Club Bulletin – Vol. 8. 1912.
  7. 1 2 "Visitor Guide to Devils Postpile and the Reds Meadow Valley, 2009-2010" (PDF). National Forest Service/National Park Service. p. 1. Retrieved 2012-03-23.
  8. "Devils Postpile – Nature & Science" . Retrieved 2012-03-23.
  9. "Devils Postpile - Animals". National Park Service. Retrieved 2010-04-23.
  10. "Devils Postpile - Plants". National Park Service. Retrieved 2010-04-23.
  11. 1 2 Grossi, Mark. "Devils Postpile National Monument". Longstreet Highroad Guide to the California Sierra Nevada. Sherpa Guides. Retrieved 2010-04-23.
  12. "Reds Meadow/Devils Postpile Shuttle Information". National Park Service. Retrieved 2017-07-06.
  13. "Devils Postpile". Visit California. 29 September 2014. Retrieved 2017-07-06.
  14. 1 2 3 4 "Devils Postpile National Park Geologic Story". USGS/National Park Service. January 2, 2000. Archived from the original on May 27, 2010. Retrieved 2010-04-23.
  15. Bassett, WA (1961). "Potassium-Argon Age of Devils Tower, Wyoming". Science. 134 (3487): 1373–3. Bibcode:1961Sci...134.1373B. doi:10.1126/science.134.3487.1373. PMID   17807346. S2CID   3101604.

PD-icon.svg This article incorporates  public domain material from websites or documents ofthe National Park Service .