Mount Baker, also known as Koma Kulshan or simply Kulshan, is a 10,781 ft (3,286 m) active glacier-covered andesitic stratovolcano in the Cascade Volcanic Arc and the North Cascades of Washington in the United States. Mount Baker has the second-most thermally active crater in the Cascade Range after Mount St. Helens. About 30 miles (48 km) due east of the city of Bellingham, Whatcom County, Mount Baker is the youngest volcano in the Mount Baker volcanic field. While volcanism has persisted here for some 1.5 million years, the current volcanic cone is likely no more than 140,000 years old, and possibly no older than 80–90,000 years. Older volcanic edifices have mostly eroded away due to glaciation.
The Mount Baker–Snoqualmie National Forest in Washington is a National Forest extending more than 140 miles (230 km) along the western slopes of the Cascade Range from the Canada–US border to the northern boundary of Mount Rainier National Park. Administered by the United States Forest Service, the forest is headquartered in Everett. There are local ranger district offices in North Bend and Skykomish.
The North Cascades are a section of the Cascade Range of western North America. They span the border between the Canadian province of British Columbia and the U.S. state of Washington and are officially named in the U.S. and Canada as the Cascade Mountains. The portion in Canada is known to Americans as the Canadian Cascades, a designation that also includes the mountains above the east bank of the Fraser Canyon as far north as the town of Lytton, at the confluence of the Thompson and Fraser Rivers.
The Sauk River is a tributary of the Skagit River, approximately 45 miles (72 km) long, in northwestern Washington in the United States. It drains an area of the high Cascade Range in the watershed of Puget Sound north of Seattle. The river is a popular destination for fly fishing. It is a National Wild and Scenic River.
The Seattle Fault is a zone of multiple shallow east–west thrust faults that cross the Puget Sound Lowland and through Seattle in the vicinity of Interstate Highway 90. The Seattle Fault was first recognized as a significant seismic hazard in 1992, when a set of reports showed that about 1,100 years ago it was the scene of a major earthquake of about magnitude 7 – an event that entered Native American oral traditions. Extensive research has since shown the Seattle Fault to be part of a regional system of faults.
The Chuckanut Formation in northwestern Washington, its extension in southwestern British Columbia, and various related formations in central Washington are fluvial sedimentary formations of Eocene age, deposited from about 54 million years ago to around 34 million years ago. The nature of the deposits and included plant fossils indicate a low-lying coastal plain with a subtropical climate; the nature of the sediments indicates metamorphic sources in northeastern Washington.
The Olympic-Wallowa lineament (OWL) is a series of geologic structures oriented from northwest to southeast for 650 km (400 mi) across Washington and northeast Oregon in the United States, passing through the Seattle area and including notable features east of the Cascade Range such as the Yakima Fold Belt and Wallowa Mountains. It was first reported by cartographer Erwin Raisz in 1945 on a relief map of the continental United States. Some geologists have questioned the existence of a geological relationship between the individual structures along the lineament suggesting it is an optical illusion. The origin of this feature in its entirety is not well understood with multiple hypotheses on the subject. The Olympic-Wallowa lineament likely predates the Columbia River Basalt Group.
The Brothers Fault Zone (BFZ) is the most notable of a set of northwest-trending fault zones including the Eugene–Denio, McLoughlin, and Vale zones that dominate the geological structure of most of Oregon. These are also representative of a regional pattern of generally northwest-striking geological features ranging from Walker Lane on the California–Nevada border to the Olympic–Wallowa Lineament in Washington; these are generally associated with the regional extension and faulting of the Basin and Range Province, of which the BFZ is considered the northern boundary.
The Puget Sound faults under the heavily populated Puget Sound region of Washington state form a regional complex of interrelated seismogenic (earthquake-causing) geologic faults. These include the:
Siletzia is a massive formation of early to middle Eocene epoch marine basalts and interbedded sediments in the forearc of the Cascadia subduction zone, on the west coast of North America. It forms the basement rock under western Oregon and Washington and the southern tip of Vancouver Island. It is now fragmented into the Siletz and Crescent terranes.
The Leech River Fault extends across the southern tip of Vancouver Island in British Columbia, Canada, creating the distinctively straight, narrow, and steep-sided valley, occupied by Loss Creek and two reservoirs, that runs from Sombrio Point due east to the Leech River, and then turns southeast to run past Victoria. It is a thrust fault that marks the northernmost exposure of the Crescent Terrane, where basalt of the Metchosin Igneous Complex is dragged under Vancouver Island by the subducting Juan de Fuca Plate. About ten kilometers north the nearly parallel San Juan Fault marks the southern limit of rock of the Wrangellia terrane, which underlies most of Vancouver Island. Between these two northeast-dipping thrust faults are the Leech River Complex and the Pandora Peak Unit. These, along with the Pacific Rim Complex further up the coast, are remnants of the Pacific Rim Terrane which was crushed between Wrangellia and Siletzia. The contact between the bottom of Wrangellia and the top of the subducted PRT continues northwest along the coast as the West Coast Fault, and southeast towards Victoria as the Survey Mountain Fault. The Leach River Fault (LRF) extends off-shore towards Cape Flattery, where the Crescent—Pacific Rim contact continues northwest as the Tofino Fault (TF).
The Yakima Fold Belt of south-central Washington, also called the Yakima fold-and-thrust belt, is an area of topographical folds raised by tectonic compression. It is a 14,000 km2 (5,400 sq mi) structural-tectonic sub province of the western Columbia Plateau Province resulting from complex and poorly understood regional tectonics. The folds are associated with geological faults whose seismic risk is of particular concern to the nuclear facilities at the Hanford Nuclear Reservation and major dams on the Columbia and Snake Rivers.
The Blue Hills just west of Bremerton, Washington, also called the Bremerton Hills, Bald Hills, and Wildcat Hills, consist of Gold Mountain, Green Mountain, and several informally named hills. Reaching an elevation of 1761 feet, a thousand feet above the glacial till that fills the Puget Lowland, they form a prominent landmark visible around the region. They are formed of uplifted blocks of marine basalts, the steep-walled canyons between the various summits being the fissures between the blocks. In addition to Gold Mountain and Green Mountain are several other prominent peaks unofficially named according to their elevation :
Hills in the Puget Lowland, between the Cascades and the Olympic Mountains, including the entire Seattle metropolitan area, are generally between 350–450 feet (110–140 m) and rarely more than 500 feet (150 m) above sea level. Hills are often notable geologically and for social reasons, such as the seven hills of Seattle.
Round Mountain is a 5,320+ ft mountain summit at the western edge of the North Cascades, in Skagit County of Washington state. It is located nine miles northwest of Darrington, Washington and is situated on land administered by the Mount Baker-Snoqualmie National Forest. Round Mountain is remarkable for its 4,780 feet of prominence which ranks as the most in Skagit County, and eighth most of all the mountains in Washington state. The nearest higher peak is Whitehorse Mountain, 7.85 miles (12.63 km) to the south-southeast. Precipitation runoff from Round Mountain drains into tributaries of the Stillaguamish River.
Mount Misch is a remote 7,435 ft mountain summit in the North Cascades, in Skagit County of Washington state. It is the highest point of the Buckindy Range, or Buckindy Ridge. It is located 19 miles east-northeast of Darrington, Washington, and 15 miles north-northwest of Glacier Peak which is one of the Cascade stratovolcanoes. It is situated in the Glacier Peak Wilderness on land administered by the Mount Baker-Snoqualmie National Forest. Mount Misch was named by mountaineer and author Fred Beckey for his friend Peter Misch (1909-1987), University of Washington geology professor and mountaineer, who was renowned for his study of the North Cascades. Precipitation runoff from Mount Misch and the unnamed Goat Creek glacier on its east slope drains into tributaries of the Suiattle River and ultimately the Skagit River.
Goat Mountain is a 6,844 ft summit in the Skagit Range which is a subset of the North Cascades of Washington state. It is located south of Mount Larrabee and north of Mount Shuksan in the Mount Baker Wilderness, which is managed by the Mount Baker-Snoqualmie National Forest. Goat Mountain has a subsidiary 6,725 ft summit known as the west peak, and remnants of what was colloquially known as the Swamp Creek Glacier rest on the northern slope between the two summits. Its nearest higher neighbor is Mount Chardonnay, 2.75 mi (4.43 km) to the east. The Silver Tip Mine was located on the south slope of the mountain near the 3,000 ft level. The mine produced silver and gold in the 1940s. Precipitation runoff from the mountain drains into tributaries of the Fraser River and the Nooksack River.
North Big Bosom Butte is a 6,384-foot (1,946-metre) mountain summit located in Whatcom County of Washington state.
Mount Buckindy is a remote 7,320-foot-elevation (2,230-meter) mountain summit located in the North Cascades, in Skagit County of Washington state. It is the second-highest point of the Buckindy Range, or Buckindy Ridge. It is set in the Glacier Peak Wilderness on land managed by the Mount Baker-Snoqualmie National Forest. It is situated 20 miles east-northeast of Darrington, Washington, and 17 miles north-northwest of Glacier Peak which is one of the Cascade stratovolcanoes. Precipitation runoff from Mount Buckindy drains south to the Suiattle River via Buck Creek and Downey Creek, and north to the Cascade River via Kindy Creek. Topographic relief is significant as the summit rises 4,700 feet above Kindy Creek in less than two miles. The mountain's toponym is a portmanteau of Buck and Kindy Creeks, and has been officially adopted by the United States Board on Geographic Names.
Hannegan caldera is a 3.72 million year old volcanic collapse structure in the North Cascades of the U.S. state of Washington. The caldera collapsed during two separate volcanic eruptions that produced as much as 140 km3 of rhyolite ash.
