The Pacific
Coast Ranges

Coast Ranges (officially gazetted as the Pacific Mountain
System[1] in the
United States

United States but referred to as the Pacific Coast
Ranges),[2] are the series of mountain ranges that stretch along the
West Coast of
North America

North America from
Alaska

Alaska south to Northern and Central
Mexico.
The Pacific
Coast Ranges

Coast Ranges are part of the North American Cordillera
(sometimes known as the Western Cordillera, or in Canada, as the
Pacific Cordillera and/or the Canadian Cordillera), which includes the
Rocky Mountains, Columbia Mountains, Interior Mountains, the Interior
Plateau, Sierra Nevada Mountains, the Great Basin mountain ranges, and
other ranges and various plateaus and basins.
The Pacific
Coast Ranges

Coast Ranges designation, however, only applies to the
Western System of the Western Cordillera,[3] which comprises the Saint
Elias Mountains, Coast Mountains, Insular Mountains, Olympic
Mountains, Cascade Range,
Oregon

Oregon Coast Range,
California

California Coast Ranges,
Transverse Ranges, Peninsular Ranges, and the Sierra Madre Occidental.
Contents
1 Other uses
2 Geography
3 Geology
4 Major ranges
5 Major icefields
6 See also
7 References
Other uses[edit]
The term Coast Range is used by the
United States

United States Geological Survey to
refer only to the ranges south from the
Strait of Juan de Fuca

Strait of Juan de Fuca in
Washington to the California-
Mexico

Mexico border; and only the ranges west
of Puget Sound, the Willamette Valley, the Sacramento and San Joaquin
valleys or '
California

California Central Valley' (thereby excluding the Sierra
Nevada and Cascade Ranges), and the Mojave (High) and Sonoran (Low)
Deserts.[4] i.e. the Pacific Border province. The same term is used
informally in
Canada
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Canada to refer to the
Coast Mountains

Coast Mountains and adjoining
inland ranges such as the Hazelton Mountains, and sometimes also the
Saint Elias Mountains.
Geography[edit]
The character of the ranges varies considerably, from the
record-setting tidewater glaciers in the ranges of Alaska, to the
rugged Central and
Southern California

Southern California ranges, the Transverse Ranges
and Peninsular Ranges, in the chaparral and woodlands ecoregion with
Oak Woodland,
Chaparral

Chaparral shrub forest or Coastal sage scrub-covering
them. The coastline is often dropping steeply into the sea with
photogenic views. Along the
British Columbia

British Columbia and
Alaska

Alaska coast, the
mountains intermix with the sea in a complex maze of fjords, with
thousands of islands. Off the
Southern California

Southern California coast the Channel
Islands archipelago of the
Santa Monica Mountains

Santa Monica Mountains extends for 160
miles (260 km).
There are coastal plains at the mouths of rivers that have punched
through the mountains spreading sediments, most notably at the Copper
River in Alaska, the
Fraser River

Fraser River in British Columbia, and the
Columbia River

Columbia River between Washington and Oregon. In California: the
Sacramento and San Joaquin Rivers' San Francisco Bay, the Santa Clara
River's
Oxnard Plain

Oxnard Plain (home to some of the most fertile soil in the
world), the Los Angeles, San Gabriel, and Santa Ana Rivers' Los
Angeles Basin - a coastal sediment-filled plain between the peninsular
and transverse ranges with sediment in the basin up to 6 miles
(10 km) deep, and the San Diego River's Mission Bay.
From the vicinity of
San Francisco Bay

San Francisco Bay north, it is common in winter
for cool unstable air masses from the Gulf of
Alaska

Alaska to make landfall
in one of the Coast Ranges, resulting in heavy precipitation, both as
rain and snow, especially on their western slopes. The same Winter
weather occurs with less frequency and precipitation in Southern
California, with the mountains' western faces and peaks causing an
eastward rainshadow that produces the arid desert regions.
Omitted from the list below, but often included is the Sierra Nevada,
a major mountain range of eastern
California

California that is separated by the
Central Valley over much of its length from the
California

California Coast
Ranges and the Transverse Ranges.[5]
Geology[edit]
On the West coast of North America, the coast ranges and the coastal
plain form the margin. Most of the land is made of terranes that have
been accreted onto the margin. In the north, the insular belt is an
accreted terrane, forming the margin. This belt extends from the
Wrangellia
Terrane in
Alaska

Alaska to the Chilliwack group of Canada.[6]
A rupture in
Rodinia

Rodinia 750 million years ago formed a passive margin in
the eastern Pacific Northwest. The breakup of
Pangea

Pangea 200 million years
ago began the westward movement of the North American plate, creating
an active margin on the western continent. As the continent drifted
West, terranes were accreted onto the west coast.[6] The timing of the
accretion of the insular belt is uncertain, although the closure did
not occur until at least 115 million years ago.[6] Other Mesozoic
terranes that accreted onto the continent include the Klamath
Mountains, the Sierra Nevada, and the Guerrero super-terrane of
western Mexico.[7] 80 to 90 million years ago the subducting Farallon
plate split and formed the
Kula Plate

Kula Plate to the North. This formed an
area in what is now Northern California, where the plates converged
forming a Mélange. North of this was the Columbia Embayment, where
the continental margin was east of the surrounding areas.[6] Many of
the major batholiths date from the late Cretaceous.[7] As the Laramide
Orogeny ended around 48 million years ago, the accretion of the
Siletzia

Siletzia terrane began in the Pacific Northwest. This began the
volcanic activity in the Cascadia subduction zone, forming the modern
Cascade Range, and lasted into the Miocene. Events here may relate to
the ignimbrite flare-up of the southern Basin and Range.[8] As
extension in the
Basin and Range Province

Basin and Range Province slowed by a change in North
American Plate movement circa 7 to 8 Million years ago, rifting began
on the Gulf of California.[8]
Although many of the ranges do share a common geologic history, the
Pacific
Coast Ranges

Coast Ranges province is not defined by geology, but rather by
geography. Many of the various ranges are composed of distinct forms
of rock from many different periods of geological time from the
Precambrian

Precambrian in parts of the
Little San Bernardino Mountains

Little San Bernardino Mountains to
10,000-year-old rock in the Cascade Range. For one example, the
Peninsular Ranges, composed of
Mesozoic

Mesozoic batholitic rock, are
geologically extremely different from the San Bernardino Mountains,
composed of a mix of
Precambrian

Precambrian metamorphic rock and Cenozoic
sedimentary rock. However, both are considered part of the Pacific
Coast Ranges

Coast Ranges due to their proximity and similar economic and social
impact on surrounding communities.
Major ranges[edit]
These are the members of the Pacific Coast Ranges, from north to
south:
Kenai Mountains, southern Alaska
Chugach Mountains, southern Alaska
Talkeetna Mountains, southern Alaska
Kenai Mountains
Yukon

Yukon Ranges, Alaska, Yukon
Wrangell Mountains, southern Alaska
Saint Elias Mountains, southern Alaska, southwestern Yukon, far
northwestern British Columbia
Alsek Ranges
Fairweather Range
Takshanuk Mountains, Haines, Alaska-area. Between Chilkat and Chilkoot
watersheds
Coast Mountains
Boundary Ranges, southeastern Alaska, northwestern British Columbia
Cheja Range (southeast of Taku/Whiting Rivers)
Chechidla Range
Chutine Icefield
Adam Mountains
Ashington Range
Burniston Range
Dezadeash Range
Florence Range
Halleck Range
Juneau Icefield
Juneau Icefield
Kakuhan Range
Lincoln Mountains
Longview Range
Peabody Mountains
Rousseau Range
Seward Mountains
Snowslide Range
Spectrum Range
Stikine Icecap
Kitimat Ranges

Kitimat Ranges BC North Coast
Pacific Ranges

Pacific Ranges BC South & Central Coast
Rainbow Range northwest Chilcotin, also classifiable as part of the
Interior Plateau
Rainbow Ridge
Pantheon Range Homathko area
Niut Range

Niut Range Homathko area
Waddington Range

Waddington Range Homathko area
Whitemantle Range Homathko area
Bendor Range
Garibaldi Ranges
Clendinning Range
Tantalus Range
Chilcotin Ranges
Dickson Range
Shulaps Range
Camelsfoot Range
Lillooet Ranges, (Fraser Canyon west bank)
Cantilever Range
Cayoosh Range
Douglas Ranges
Front Ranges (North Shore Mountains)
Insular Mountains, British Columbia
Vancouver Island Ranges, British Columbia
Queen Charlotte Mountains, British Columbia
Mt. Constance, Olympic Mountains
Olympic Mountains, Washington
Cascade Range,
British Columbia

British Columbia (Fraser Canyon east bank), Washington,
Oregon

Oregon and California
Oregon

Oregon Coast Range, Oregon
Northern
Oregon

Oregon Coast Range
Central
Oregon

Oregon Coast Range
Southern
Oregon

Oregon Coast Range
Calapooya Mountains, Oregon
Klamath-Siskiyou, Oregon, Northern California
Klamath Mountains, Oregon, Northern California
Siskiyou Mountains, Oregon, Northern California
Trinity Alps

Trinity Alps and Salmon Mountains, Northern California
Yolla Bolly Mountains, Northern California
Northern Coast Ranges, Northern California
King Range, Northern California
Mendocino Range, Northern California
Klamath Mountains
Mayacamas Mountains, Northern California
Marin Hills, Northern California, (including Mount Tamalpais)
Central
California

California Coast Ranges, Central California
Santa Cruz Mountains, Central California
Diablo Range, Central California
Gabilan Range, Central California
Santa Lucia Range, Central California
Temblor Range, Central California
Caliente Range, Central California
Transverse Ranges, Southern California
Sierra Madre Mountains, Southern California
Sierra Pelona Mountains, Southern California
San Rafael Mountains
San Emigdio Mountains, Southern California
San Rafael Mountains, Southern California
Santa Ynez Mountains, Southern California
Tehachapi Mountains, Southern California
Topatopa Mountains, Southern California
Santa Susana Mountains, Southern California
Simi Hills, Southern California
Santa Monica Mountains, Southern California
Chalk Hills, Southern California
San Gabriel Mountains, Southern California
Puente Hills
San Rafael Hills, Southern California
Puente Hills, Southern California
San Bernardino Mountains, Southern California
Little San Bernardino Mountains, Southern California
Peninsular Ranges,
Southern California

Southern California and Mexico
Santa Ana Mountains, Southern California
Chino Hills, Southern California
San Jacinto Mountains, Southern California
Palomar Mountain Range, Southern California
Laguna Mountains, Southern California
Sierra Juarez, Northern Baja California, Mexico
Sierra San Pedro Martir, Central Baja California, Mexico
Sierra de San Borja, Central Baja California, Mexico
Sierra de San Francisco, Central Baja California, Mexico
Sierra de Guadalupe cave paintings, Central Baja California, Mexico
Sierra de la Giganta, Southern Baja California, Mexico
Sierra de la Laguna, Southern Baja California, Mexico
Sierra Madre Occidental, Northwestern Mexico
Major icefields[edit]
These are not named as ranges, but amount to the same thing. The
Pacific
Coast Ranges

Coast Ranges are home to the largest temperate-latitude
icefields in the world.
Harding Icefield
Sargent Icefield
Harding Icefield
Bagley Icefield
Kluane Icefields
Juneau Icefield
Stikine Icecap
Ha-Iltzuk Icefield

Ha-Iltzuk Icefield (Silverthrone Glacier)
Monarch Icefield
Waddington Icefield
Homathko Icefield
Lillooet Icecap (Lillooet Crown)
Pemberton Icefield
Only the largest icefields are listed above; smaller icefields may be
listed on the various range pages. Formally unnamed icefields are not
listed
See also[edit]
Wikimedia Commons has media related to
Pacific Coast Ranges.
List of Pacific
Coast Ranges

Coast Ranges topics
Coast Range (ecoregion)
California Coast Ranges

California Coast Ranges (geomorphic province)
Coast Ranges

Coast Ranges (geomorphic province)
United States

United States physiographic regions
References[edit]
^ Physiographic regions of the United States, USGS
^ Merriam-Webster's collegiate encyclopedia, page 361
(Merriam-Webster, 2000).
^ S. Holland, Landforms of British Columbia, BC Govt. 1976.
^ "Coast Ranges". Geographic Names Information System. United States
Geological Survey. Retrieved 2007-07-30.
^ "Pacific mountain system". Britannica Online Encyclopedia.
Encyclopædia Britannica. Retrieved 2007-09-29.
^ a b c d Townsend, Catherine; Figge, John (2002). "Northwest
Origins". The Burke Museum.
^ a b Dickinson, William (2004). "Evolution of the North American
Cordillera" (PDF). Annual Review of Earth and Planetary Sciences. 32:
13–45. doi:10.1146/annurev.earth.32.101802.120257. Archived from the
original (PDF) on 4 January 2014. Retrieved 9 April 2013.
^ a b Humphreys, Eugene (2009). "Relation of flat subduction to
magmatism and deformation in the Western United States". GSA.
access-date= req