The Pacific Coast Ranges are the series of mountain ranges that stretch along the West Coast of North America from Alaska south to Northern and Central Mexico. Although they are commonly thought to be the westernmost mountain range of the continental United States and Canada, the geologically distinct Insular Mountains of Vancouver Island lie farther west.
The Garibaldi Volcanic Belt is a northwest–southeast trending volcanic chain in the Pacific Ranges of the Coast Mountains that extends from Watts Point in the south to the Ha-Iltzuk Icefield in the north. This chain of volcanoes is located in southwestern British Columbia, Canada. It forms the northernmost segment of the Cascade Volcanic Arc, which includes Mount St. Helens and Mount Baker. Most volcanoes of the Garibaldi chain are dormant stratovolcanoes and subglacial volcanoes that have been eroded by glacial ice. Less common volcanic landforms include cinder cones, volcanic plugs, lava domes and calderas. These diverse formations were created by different styles of volcanic activity, including Peléan and Plinian eruptions.
The Chilcotin Ranges are a subdivision of the Pacific Ranges of the Coast Mountains. They lie on the inland lea of the Pacific Ranges, abutting the Interior Plateau of British Columbia. Their northwestern end is near the head of the Klinaklini River and their southeast end is the Fraser River just north of Lillooet; their northern flank is the edge of the Plateau while their southern is the north bank of the Bridge River. In some reckonings they do not go all the way to the Fraser but end at the Yalakom River, which is the North Fork of the Bridge.
The Pantheon Range is a subrange of the Pacific Ranges of the Coast Mountains in British Columbia. It is located between the edge of the Chilcotin Plateau at Tatla Lake on its northeast and the Klinaklini River on its west, with a southeastern boundary along Mosley Creek, a major tributary of the Homathko River. The range is 5550 km2 in area and extremely rugged, with many sharp, glaciated peaks.
The Waddington Range is a subrange of the Pacific Ranges of the Coast Mountains in southwestern British Columbia, Canada. It is only about 4,000 km2 in area, relatively small in area within the expanse of the range, but it is the highest area of the Pacific Ranges and of the Coast Mountains, being crowned by its namesake Mount Waddington 4,019 m (13,186 ft). The Waddington Range is also extremely rugged and more a complex of peaks than a single icefield, in contrast to the other huge icefield-massifs of the southern Coast Mountains, which are not so peak-studded and tend to have more contiguous icemasses.
The Niut Range is 3600 km2 in area. It is a subrange of the Pacific Ranges of the Coast Mountains of British Columbia, although in some classifications it is considered part of the Chilcotin Ranges. The Niut is located in the angle of the Homathko River and its main west fork, Mosley Creek. It is isolated, island-like, by those rivers from its neighbour ranges, as both streams have their source on the Chilcotin Plateau in behind the range. Razorback Mountain is its highest peak.
The Cariboo Plateau is a volcanic plateau in south-central British Columbia, Canada. It is part of the Fraser Plateau that itself is a northward extension of the North American Plateau. The southern limit of the plateau is the Bonaparte River although some definitions include the Bonaparte Plateau between that river and the Thompson, but it properly is a subdivision of the Thompson Plateau. The portion of the Fraser Plateau west of the Fraser River is properly known as the Chilcotin Plateau but is often mistakenly considered to be part of the Cariboo Plateau, which is east of the Fraser.
The Chilcotin Plateau is part of the Fraser Plateau, a major subdivision of the Interior Plateau of British Columbia. The Chilcotin Plateau is physically near-identical with the region of the same name, i.e. "the Chilcotin", which lies between the Fraser River and the southern Coast Mountains and is defined by the basin of the Chilcotin River and so includes montane areas beyond the plateau. East of the Chilcotin Plateau, across the Fraser River, is the Cariboo Plateau, while to the north beyond the West Road (Blackwater) River is the Nechako Plateau. West and south of the Chilcotin Plateau are various subdivisions of the Coast Mountains, including the Chilcotin Ranges which lie along the plateau's southwest.
The Mount Meager massif is a group of volcanic peaks in the Pacific Ranges of the Coast Mountains in southwestern British Columbia, Canada. Part of the Cascade Volcanic Arc of western North America, it is located 150 km (93 mi) north of Vancouver at the northern end of the Pemberton Valley and reaches a maximum elevation of 2,680 m (8,790 ft). The massif is capped by several eroded volcanic edifices, including lava domes, volcanic plugs and overlapping piles of lava flows; these form at least six major summits including Mount Meager which is the second highest of the massif.
Mount Price is a small stratovolcano in the Garibaldi Ranges of the Pacific Ranges in southwestern British Columbia, Canada. It has an elevation of 2,049 m (6,722 ft) and rises above the surrounding landscape on the western side of Garibaldi Lake in New Westminster Land District. The mountain contains a number of subfeatures, including Clinker Peak on its western flank, which was the source of two thick lava flows between 15,000 and 8,000 years ago that ponded against glacial ice. These lava flows are structurally unstable, having produced large landslides as recently as the 1850s. A large provincial park surrounds Mount Price and other volcanoes in its vicinity. It lies within an ecological region that surrounds much of the Pacific Ranges.
Mount Silverthrone, officially named Silverthrone Mountain, is a mountain in the Pacific Ranges of the Coast Mountains of British Columbia, Canada, located over 320 km (200 mi) northwest of the city of Vancouver and about 50 km (30 mi) west of Mount Waddington, British Columbia, Canada. It is the highest peak in the Ha-Iltzuk Icefield, which is the largest icefield in the Coast Mountains south of the Alaska Panhandle.
Black Dome Mountain is the northernmost summit of the Camelsfoot Range, which lies along the west side of the Fraser River, north of Lillooet, British Columbia, Canada. It is an ancient butte-like volcano located in the formation known as the Chilcotin Group, which lie between the Pacific Ranges of the Coast Mountains and the mid-Fraser River in British Columbia, Canada.
The Ha-Iltzuk Icefield is an icefield in the central Pacific Ranges of the Coast Mountains in British Columbia, Canada. It is the largest icefield in the Coast Mountains south of the Alaska Panhandle, with an area of 3,610 km2 (1,390 sq mi). It is located on the west side of the Klinaklini River and the Waddington Range. The highest summit in the icefield is Mount Silverthrone, which is a mountain on the northeast edge of a circular, 20 km (12 mi) wide, deeply dissected caldera complex called the Silverthrone Caldera.
The geology of the Pacific Northwest includes the composition, structure, physical properties and the processes that shape the Pacific Northwest region of North America. The region is part of the Ring of Fire: the subduction of the Pacific and Farallon Plates under the North American Plate is responsible for many of the area's scenic features as well as some of its hazards, such as volcanoes, earthquakes, and landslides.
The Lillooet Icecap, also called the Lillooet Icefield or the Lillooet Crown, is a large icefield in the Pacific Ranges of the Coast Mountains in southwestern British Columbia, Canada. It is about 90 km (56 mi) northwest of the towns of Pemberton and Whistler, and about 175 km (109 mi) north of Vancouver, British Columbia. The Lillooet Icecap is one of the largest of several large icefields in the Pacific Ranges which are the largest temperate-latitude glacial fields in the world. At its maximum extent including its glacial tongues it measures 30 km (19 mi) east to west and 20 km (12 mi) north to south; its central icefield area is approximately 15 km (9 mi) in diameter.
The Homathko Icefield is an icefield in British Columbia, Canada. Officially named the Homathko Snowfield from 1950 until the current name was adopted in 1976, it is one of the largest icefields in the southern half of the Coast Mountains, with an area of over 2,000 km2 (770 sq mi). It is located between Chilko Lake and the Homathko River, and lies across the Great Canyon of that river to the east of the Waddington Range. Although adjacent to Mount Queen Bess, the Homathko Icefield is largely an expanse of ice, about 30 km (19 mi) across, ringed by relatively minor peaks and distinguished, relative to the other Coast Mountains icefields, by lack of any major ones. The Lillooet Icecap and the Compton Névé, both similar in size to the Homathko Icefield but much more peak-studded, lie to the Homathko Icefield's southeast across the Southgate River which bends around the icefield-massif's southern flank to reach the head of Bute Inlet adjacent to the mouth of the Homathko River. The icefield is essentially one large ice-girt montane plateau between these two rivers.
The Silverthrone Caldera is a potentially active caldera complex in southwestern British Columbia, Canada, located over 350 kilometres (220 mi) northwest of the city of Vancouver and about 50 kilometres (31 mi) west of Mount Waddington in the Pacific Ranges of the Coast Mountains. The caldera is one of the largest of the few calderas in western Canada, measuring about 30 kilometres (19 mi) long (north-south) and 20 kilometres (12 mi) wide (east-west). Mount Silverthrone, an eroded lava dome on the caldera's northern flank that is 2,864 metres (9,396 ft) high, may be the highest volcano in Canada.
The Canadian Cascade Arc, also called the Canadian Cascades, is the Canadian segment of the North American Cascade Volcanic Arc. Located entirely within the Canadian province of British Columbia, it extends from the Cascade Mountains in the south to the Coast Mountains in the north. Specifically, the southern end of the Canadian Cascades begin at the Canada–United States border. However, the specific boundaries of the northern end are not precisely known and the geology in this part of the volcanic arc is poorly understood. It is widely accepted by geologists that the Canadian Cascade Arc extends through the Pacific Ranges of the Coast Mountains. However, others have expressed concern that the volcanic arc possibly extends further north into the Kitimat Ranges, another subdivision of the Coast Mountains, and even as far north as Haida Gwaii.
The Mount Cayley volcanic field (MCVF) is a remote volcanic zone on the South Coast of British Columbia, Canada, stretching 31 km (19 mi) from the Pemberton Icefield to the Squamish River. It forms a segment of the Garibaldi Volcanic Belt, the Canadian portion of the Cascade Volcanic Arc, which extends from Northern California to southwestern British Columbia. Most of the MCVF volcanoes were formed during periods of volcanism under sheets of glacial ice throughout the last glacial period. These subglacial eruptions formed steep, flat-topped volcanoes and subglacial lava domes, most of which have been entirely exposed by deglaciation. However, at least two volcanoes predate the last glacial period and both are highly eroded. The field gets its name from Mount Cayley, a volcanic peak located at the southern end of the Powder Mountain Icefield. This icefield covers much of the central portion of the volcanic field and is one of the several glacial fields in the Pacific Ranges of the Coast Mountains.
