Hughes Mountain and the Hughes Mountain State Natural Area are located in southern Washington County, Missouri (Sections 28 and 33, T36N R3E) just south of the Big River and Highway M on Cedar Creek Road in the
St. Francois Mountains
The St. Francois Mountains in southeast Missouri are a mountain range of Precambrian igneous mountains rising over the Ozark Plateau. This range is one of the oldest exposures of igneous rock in North America.
The name of the range is spelled out ...
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 of the mountain, including the
rhyolite
Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...
The area around Hughes Mountain was first settled ca 1810 by John Hughes, his wife (Susannah) and their children, resulting in the mountain being named Hughes Mountain. The mountain itself remained public land until 1861 when purchased by John Hughes's son, Mahlon Hughes and afterwards remained in the Hughes family until it was purchased by the Missouri Conservation Commission in 1982. At that time it was designated a State Natural Area.Missouri Department of Conservation -- Missouri Dept. of Natural Resources, Natural Area Nomination Form 1982
Hughes Mountain State Natural Area
The Hughes Mountain State Natural Area can be accessed by the public via a 1.4 mile (2.253 kilometers) linear/loop trail with the trail head in a small parking area on Highway M southeast of Irondale. Within the Hughes Mountain Natural Area is a glade with an outcrops of
Precambrian
The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the ...
rhyolite
Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...
displaying columnar jointing, and designated the ''Devil's Honeycomb''. Devil's Honeycomb is listed in the book, ''Geographic Wonders and Curiosities of Missouri.'' The natural area is divided between forest land (about 2/3 the total area) containing three types of forests, and glades(about 1/3 the total area).
blackjack oak
''Quercus marilandica'', the blackjack oak, is a small oak, one of the red oak group ''Quercus'' sect. ''Lobatae''. It is native to the eastern and central United States.
Description
''Quercus marilandica'' is a small deciduous tree growing to ...
black hickory
''Carya texana'', or black hickory, for its dark colored bark, is a North American tree in the walnut family, Juglandaceae. It is endemic to the United States, found primarily in the southern Great Plains and the Lower Mississippi Valley. It is ...
,
farkleberry
''Vaccinium arboreum'' (sparkleberry or farkleberry) is a species of ''Vaccinium'' native to the southeastern and south-central United States, from southern Virginia west to southeastern Nebraska, south to Florida and eastern Texas, and north to ...
,
winged elm
''Ulmus alata'', the winged elm or wahoo, is a small- to medium-sized deciduous tree endemic to the woodlands of the southeastern and south-central United States. The species is tolerant of a wide range of soils, and of ponding, but is the leas ...
,
lowbush blueberry
Blueberries are a widely distributed and widespread group of perennial flowering plants with blue or purple berries. They are classified in the section ''Cyanococcus'' within the genus ''Vaccinium''. ''Vaccinium'' also includes cranberries, bi ...
,
service berry
''Amelanchier'' ( ), also known as shadbush, shadwood or shadblow, serviceberry or sarvisberry (or just sarvis), juneberry, saskatoon, sugarplum, wild-plum or chuckley pear,A Digital Flora of Newfoundland and Labrador Vascular Plants/ref> is a g ...
,
red elm
''Ulmus rubra'', the slippery elm, is a species of elm native to eastern North America.
Other common names include red elm, gray elm, soft elm, moose elm, and Indian elm.
Description
''Ulmus rubra'' is a medium-sized deciduous tree with a spre ...
winged sumac
''Rhus copallinum'' (''Rhus copallina'' is also used but, this is not consistent with the rules of the International Association for Plant Taxonomy), the winged sumac, shining sumac, dwarf sumac or flameleaf sumac, is a species of flowering pl ...
rough buttonweed
''Hexasepalum teres'' is a species of flowering plant in the coffee family known by the common names poorjoe and rough buttonweed. This annual plant is native to Mexico, Central America, South America, the West Indies and the United States fro ...
,
broomsedge
''Andropogon virginicus'' is a species of grass known by several common names, including broomsedge bluestem, yellowsedge bluestem and (in Australia, because it was introduced to that country after being used as packaging for bottles of American ...
,
poverty grass Poverty grass is a common name for several plants and may refer to:
*Any of several grasses that grow in poor or sandy soil, for example:
** '' Aristida dichotoma'', Shinner's three-awn
** ''Eremochloa bimaculata''
** ''Sporobolus vaginiflorus'', ...
,
yellow star grass
''Hypoxis'' is a genus of flowering plants of the family Hypoxidaceae. The genus has an " almost cosmopolitan" distribution, occurring in Africa, the Americas, Asia, and Australia.Singh, Y. (Natal Herbarium, Durban)''Hypoxis''.PlantZAfrica.com: ...
flame flower
''Talinum'' is a genus of herbaceous succulent plants in the family Talinaceae (formerly in the family Portulacaceae) whose common names include flameflower. Several species bear edible leaves, and ''Talinum fruticosum'' is widely grown in trop ...
wild hyacinth Wild hyacinth may refer to:
*''Hyacinthoides non-scripta'', a European species also called the common bluebell
*''Camassia'', a genus of six North American species
*''Dipterostemon capitatus'', a species from North America, the only species in the g ...
lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.fence and
collared
Collar may refer to:
Human neckwear
*Clerical collar (informally ''dog collar''), a distinctive collar used by the clergy of some Christian religious denominations
*Collar (clothing), the part of a garment that fastens around or frames the neck
...
prairie warbler
The prairie warbler (''Setophaga discolor'') is a small songbird of the New World warbler family.
Description
These birds have yellow underparts with dark streaks on the flanks, and olive overparts with rusty streaks on the back; they have a ye ...
s.
Geology
Hughes Mountain is a peak in the
St. Francois Mountains
The St. Francois Mountains in southeast Missouri are a mountain range of Precambrian igneous mountains rising over the Ozark Plateau. This range is one of the oldest exposures of igneous rock in North America.
The name of the range is spelled out ...
rhyolite
Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...
rocks of these mountains formed 1.485 billion years ago during the
Proterozoic
The Proterozoic () is a geological eon spanning the time interval from 2500 to 538.8million years ago. It is the most recent part of the Precambrian "supereon". It is also the longest eon of the Earth's geologic time scale, and it is subdivided ...
Eon when the area was volcanically active.Denison, Rodger E., et al., ''Geology and Geochemistry of the Precambrian Rocks in the Central Interior Region of the United States'', Geological Survey Professional Paper 1241-C, 1984, pp. C8-10 Hughes Mountain is formed of extrusive
rhyolite
Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...
which fractured into vertical joints when it cooled, creating polygonal columns. These columns have from four to six sides and are up to three feet (0.91 m) tall. When viewed from above they resemble a honeycomb.
Columnar jointing is not limited to rhyolite formations. The Devils Honeycomb is a smaller example of the sort of columnar jointing found at Devils Tower National Monument in Wyoming,
Devils Postpile
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 ...
* Missouri Department of Conservation—Missouri Dept. of Natural Resources, Natural Area Nomination Form 1982
* Geologic Wonders and Curiosities of Missouri, By Thomas Robinson Beveridge, Missouri Division of Geology and Land Survey, 1978, pgs 18-20
* The Missouri Conservationist, Vol. 48 No. 8 September 1987, pgs 10-14, article by Richard Thom
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