Needle Rock Natural Area
is located at the western edge of the
West Elk Mountains
The West Elk Mountains are a high mountain range in the west-central part of the U.S. state of Colorado. They lie primarily within the Gunnison National Forest, and part of the range is protected as the West Elk Wilderness. The range is primarily l ...
of
Colorado
Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...
. The surrounding terrain is characterized by
laccolithic mountains flanked by precipitous cliffs, extensive talus aprons, forested mesas, canyons, and spacious, well-watered intermontane basins.
Needle Rock is an intrusive plug of
monzonite
Monzonite is an igneous intrusive rock, formed by slow cooling of underground magma that has a moderate silica content and is enriched in alkali metal oxides. Monzonite is composed mostly of plagioclase and alkali feldspar.
Syenodiorite is an o ...
porphyry[Noe, D. C., and Alexander T. Klink. “OF-15-06 Geologic Map of the Crawford Quadrangle, Delta and Montrose Counties, Colorado.” Geologic, 1:24,000. Open File Report. Golden, CO: Colorado Geological Survey, 2015.] cropping out east-northeast (
bearing 68°) of the
Town of Crawford in
Delta County,
Colorado
Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...
,
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
. At an elevation of ,
[The elevation of Needle Rock includes an adjustment of +1.473 m (+4.83 ft) from NGVD 29 to NAVD 88.] the towering rock spire stands tall above the floor of the
Smith Fork of the
Gunnison River
The Gunnison River is located in western Colorado, United States and is one of the largest tributaries of the Colorado River.
Description
The river flows east to west and has a drainage area of according to the USGS. The drainage basin of ...
valley. The massive rock feature originated in the
Oligocene geological epoch when
magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...
intruded
Intrusive rock is formed when magma penetrates existing rock, crystallizes, and solidifies underground to form '' intrusions'', such as batholiths, dikes, sills, laccoliths, and volcanic necks.Intrusive RocksIntrusive rocks accessdate: March 2 ...
between existing
sedimentary rock
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...
s as the crown of a buried laccolith
or possibly the underlying conduit of a laccolith.
Subsequent erosion has exposed the prominent rock formation seen in the natural area today.
The Needle Rock Natural Area is managed by the
Bureau of Land Management.
BLM Needle Rock Natural Area Webpage
/ref>
See also
*West Elk Mountains
The West Elk Mountains are a high mountain range in the west-central part of the U.S. state of Colorado. They lie primarily within the Gunnison National Forest, and part of the range is protected as the West Elk Wilderness. The range is primarily l ...
* List of Colorado mountain ranges
* List of Colorado mountain summits
**List of Colorado fourteeners
This is a list of mountain peaks in the U.S. State of Colorado that exceed of elevation.
In the mountaineering parlance of the Western United States, a ''fourteener'' is a mountain peak with an elevation of at least 14,000 feet. This is a co ...
** List of Colorado 4000 meter prominent summits
**List of the most prominent summits of Colorado
The following sortable table comprises the 100 most topographically prominent mountain peaks of the U.S. State of Colorado.
Topographic elevation is the vertical distance above the reference geoid, a mathematical model of the Earth's sea le ...
*List of Colorado county high points
This is a list of all 64 counties of the U.S. State of Colorado by their points of highest elevation. Of the 50 highest county high points in the United States, 30 are located in Colorado. The highest point in Colorado is the summit of Mount ...
References
External linksNeedle Rock Article - summitpost.org
West Elk Mountains
Mountains of Delta County, Colorado
Protected areas of Delta County, Colorado
Mountains of Colorado
North American 2000 m summits
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