| Devils Postpile National Monument | |
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IUCN Category III (Natural Monument)
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| Location | Madera County, California, USA |
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| Nearest city | Mammoth Lakes, CA |
| Coordinates | 37°37′28″N 119°5′4″W / 37.62444°N 119.08444°WCoordinates: 37°37′28″N 119°5′4″W / 37.62444°N 119.08444°W |
| Area | 798 acres (323 ha) |
| Established | July 6, 1911 |
| Visitors | 114,788 (in 2004) |
| Governing body | National Park Service |
Devils Postpile is a dark cliff of columnar basalt near Mammoth Mountain in extreme northeastern Madera County in eastern California. The postpile was created by a lava flow sometime between less than 100,000 years ago (according to current potassium-argon dating) to 700,000 years ago (according to other dating methods). 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, was impounded by a moraine, and reached a thickness of 400 feet (newer estimate) to 600 feet (older estimate). In any event, 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 cool; the joints develop when the lava contracts during the cooling process.
A glacier later removed much of this mass of rock and left a nicely polished surface on top of the Postpile with very noticeable glacial striations and glacial polish.
Devils Postpile was once part of Yosemite National Park, but discovery of gold near Mammoth Lakes prompted a boundary change that left the Postpile on adjacent public land. A proposal to build a hydroelectric dam later called for blasting the Postpile into the river. Influential Californians, including Walter L. Huber, persuaded the federal government to stop the demolition and in 1911, President William Howard Taft made the area into a United States National Monument. The John Muir Trail and Pacific Crest Trail pass through the monument.
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 on account of 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.[1] Compared with other examples of columnar jointing, the Postpile has more hexagonal columns. Another thing that places the Postpile in a special category is the lack of horizontal jointing.
Several stones from the Devil's Postpile can be seen at the entrance to the United States Geological Survey headquarters lot in Reston, Virginia.
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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 Giant's Causeway in Northern Ireland, Fingal's Cave in Scotland, the Garni gorge in Armenia, the Cyclopean Isles near Sicily, Devils Tower National Monument in Wyoming, Sheepeater Cliff at Yellowstone National Park in Wyoming, Basalt Prisms in Hidalgo, Mexico, the "Organ Pipes" formation on Mount Cargill in New Zealand, Gilbert Hill in Mumbai, Organ Pipes National Park in Australia and the "Columnar Cape" (Russian: Mis Stolbchaty) on Kunashir, the southernmost of the Kurile Islands in Russia.
Ancient columnar basalt can be seen in a high desert dry river falls area just north of Lajitas, Texas. The columns are accessible on horseback, on foot, or mountain bike via trail.
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Devils Postpile National Monument [1] is a United States National Monument located in the Sierra Nevada region of the state of California. 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 Devils Postpile 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 60 feet high and display an unusual symmetry.
Due to winter conditions in the mountains the monument is open only during the summer season. Opening dates vary depending on snowfall, but in 2006 the monument was open to visitors from June 27 until October 31. Outside of that time access by car is not possible, although visitors traveling by ski or on foot may still be able to enter the park.
The closest commercial airport is in Reno. From Reno, drive south on U.S. Highway 395 for approximately 3 hours (170 miles) to State Route 203.
From U.S. Highway 395, drive 10 miles west on S.R. 203 to Minaret Vista and then another 8 miles on a paved, steep mountain road. Please note that this road is single lane for approximately 3 miles.
There is a mandatory shuttle bus that operates from mid-June through September. To use the shuttle park at the Mammoth Mountain Ski Area. The shuttle does not need to be used by visitors who meet any of the following criteria:
Shuttle bus tickets can be purchased at the Forest Service Adventure Center located in the Mammoth Mountain Ski Area Gondola Building adjacent to the Mammoth Mountain Inn at the top of Highway 203. Buses run every 20 or 30 minutes.
For those visitors keen to bike down to the Postpile, bicycles are allowed down the road free of charge. If, however, visitors choose not to ride back out of the Valley and opt to use the shuttle instead, they must pay the transportation fee. The shuttle buses are equipped to transport bicycles.
All visitors to the Reds Meadow Valley area, whether they take the mandatory shuttle bus or drive their personal vehicle, must pay a transportation fee. The fees are as follows:
Season passes are available for $35. Note since the fees charged are transportation fees (and not park entry fees) that Golden Passports and National Park Passes are not valid for this transportation fee under the Federal Lands Recreation Enhancement Act. Fees are valid for the duration of the visit.
The park is a popular entry point for treks into the Ansel Adams and John Muir wilderness areas. Wilderness permits are required for all overnight stays in the backcountry. Backpackers are encouraged to acquire their wilderness permits from the Inyo National Forest, although the staff at Devils Postpile can issue first-come, first-served permits for trips originating out of trailheads within Reds Meadow Valley. These walk-in permits are free of charge.
Permits can be issued for the day of entry or the day before (starting at 11:00am). Reservations are not available through the Devils Postpile Ranger Station. Backcountry users interested in obtaining a reservation must contact the Inyo National Forest's Wilderness Permit Office at (760) 873-2485.
Bear cannisters are required for most destinations. Devils Postpile has a limited number of these available for rent for $3.00/day.
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