The Granite Mountains are a small

mountain range A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have arise ...

San Bernardino County, California San Bernardino County (), officially the County of San Bernardino, is a County (United States), county located in the Southern California, southern portion of the U.S. state of California, and is located within the Inland Empire area. As of the ...

, USA, located in the

Mojave Desert The Mojave Desert ( ; mov, Hayikwiir Mat'aar; es, Desierto de Mojave) is a desert in the rain shadow of the Sierra Nevada mountains in the Southwestern United States. It is named for the indigenous Mojave people. It is located primarily in ...

. They are in the

Mojave National Preserve Mojave National Preserve is a United States National Preserve located in the Mojave Desert of San Bernardino County, California, USA, between Interstate 15 in California, Interstate 15 and Interstate 40. The preserve was established October 31 ...

, in the

National Park Service The National Park Service (NPS) is an agency of the United States federal government within the U.S. Department of the Interior that manages all national parks, most national monuments, and other natural, historical, and recreational propertie ...

system. The University of California operates th
Granite Mountain Natural Reserve
on 9000 acres of land within the Mojave National Preserve. The Granite Mountains Natural Reserve is a research and teaching center that was established by the late Professo
Dr. Kenneth Norris
of U.C. Santa Cruz in 1978 and is now managed out of UC Riverside. Students and faculty have completed extensive studies of the natural history of the Granite Mountains since the reserve's inception. This is one of 37 reserves in th
UC Natural Reserve System

Geography

The Granite Mountains are north of

Interstate 40 Interstate 40 (I-40) is a major east–west Interstate Highway running through the south-central portion of the United States. At a length of , it is the third-longest Interstate Highway in the country, after I-90 and I-80. From west to ea ...

and historic

Route 66 U.S. Route 66 or U.S. Highway 66 (US 66 or Route 66) was one of the original highways in the United States Numbered Highway System. It was established on November 11, 1926, with road signs erected the following year. The h ...

. The

Providence Mountains The Providence Mountains are found in the eastern Mojave Desert of San Bernardino County, California, U.S. The range reaches an elevation of at Edgar Peak and is home to the Mitchell Caverns Natural Preserve in the Providence Mountains State Re ...

are adjacent to the northeast. The

Bristol Mountains The Bristol Mountains are found in the Mojave Desert of California, USA, just west of Mojave National Preserve. The range, which reaches an elevation of 3,874 feet (1,181 m), is located in San Bernardino County, and crosses Interstate 40 between L ...

are directly to the west, the Old Woman Mountains are to the southeast, and

Pisgah Crater Pisgah Crater, or Pisgah Volcano, is a young volcano, volcanic cinder cone rising above a lava plain in the Mojave Desert, between Barstow, California, Barstow and Needles, California in San Bernardino County, California. The volcanic peak is ...

and the

Bullion Mountains The Bullion Mountains are located in the Mojave Desert of California southeast of the city of Barstow. The mountain range stretches for approximately 50 miles in a northwest-southeasterly direction north of Joshua Tree and Twentynine Palms. Sinc ...

are to the southwest. The Mountains lie east of the small community of Kelso, northeast of

Ludlow Ludlow () is a market town in Shropshire, England. The town is significant in the history of the Welsh Marches and in relation to Wales. It is located south of Shrewsbury and north of Hereford, on the A49 road which bypasses the town. The t ...

, and north of

Amboy Amboy may refer to: Places * Amboy, Córdoba, village in Calamuchita Department, Córdoba province, Argentina United States * Amboy Crater, feature in Mojave National Preserve, California Settled U.S. places * Amboy, California * Amboy, Ge ...

. The range stretches from Granite Pass () to Budweiser Wash ().

Geology

Some of the more striking rock formations in the

lie in the Granite Mountains. These

granitic A granitoid is a generic term for a diverse category of coarse-grained igneous rocks that consist predominantly of quartz, plagioclase, and alkali feldspar. Granitoids range from plagioclase-rich tonalites to alkali-rich syenites and from quart ...

rocks have eroded into unusual rounded shapes that include spires, perched boulders, and curved cliff faces. Granitic rocks represent the roots of ancient continental-margin volcanic systems. Most of the granitic rock in the Mojave Desert is late

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceo ...

in age (80 to 180 million years old). The granites formed at depth within a volcanically active mountain range comparable in geologic setting to the

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

chain in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

. The granitoids formed by the slow cooling and solidification of molten

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 ...

bodies that developed above sinking slabs of

oceanic crust Oceanic crust is the uppermost layer of the oceanic portion of the tectonic plates. It is composed of the upper oceanic crust, with pillow lavas and a dike complex, and the lower oceanic crust, composed of troctolite, gabbro and ultramafic cumu ...

overridden by the edge of the continent. At least 55 or 60 million years elapsed between the crystallization of the last

magma bodies and deposition of the youngest-preserved overlying strata. Several

spring Spring(s) may refer to: Common uses * Spring (season), a season of the year * Spring (device), a mechanical device that stores energy * Spring (hydrology), a natural source of water * Spring (mathematics), a geometric surface in the shape of a ...

s exist in the Granite Mountains, though they may not flow year round.

References

America's Volcanic Past - Mojave National Preserve
(USGS PD source) {{authority control Mojave National Preserve Mountain ranges of the Mojave Desert Protected areas of the Mojave Desert Mountain ranges of San Bernardino County, California Protected areas of San Bernardino County, California

Geography

Geology

See also

References