The Columbia River is the largest river in the Pacific Northwest region of North America. The river forms in the Rocky Mountains of British Columbia, Canada. It flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state of Oregon before emptying into the Pacific Ocean. The river is 1,243 mi (2,000 km) long, and its largest tributary is the Snake River. Its drainage basin is roughly the size of France and extends into seven states of the United States and one Canadian province. The fourth-largest river in the United States by flow, the Columbia has the greatest flow of any river into the eastern Pacific.
The Snake River is a major river in the interior Pacific Northwest region of the United States. About 1,080 miles (1,740 km) long, it is the largest tributary of the Columbia River, which is the largest North American river that empties into the Pacific Ocean. Beginning in Yellowstone National Park, western Wyoming, it flows across the arid Snake River Plain of southern Idaho, the rugged Hells Canyon on the borders of Idaho, Oregon and Washington, and finally the rolling Palouse Hills of southeast Washington. It joins the Columbia River just downstream from the Tri-Cities, Washington, in the southern Columbia Basin.
The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as many of those in the North Cascades, and the notable volcanoes known as the High Cascades. The small part of the range in British Columbia is referred to as the Canadian Cascades or, locally, as the Cascade Mountains. The highest peak in the range is Mount Rainier in Washington at 14,411 feet (4,392 m).
The Pacific Northwest, sometimes referred to as Cascadia, is a geographic region in Western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though no official boundary exists, the most common conception includes the U.S. states of Oregon, Washington, and the Canadian province of British Columbia. Some broader conceptions reach north into Alaska and Yukon, south into northern California, and east into western Montana and Idaho. Other conceptions may be limited to the coastal areas west of the Cascade and Coast mountains.
Cascadia and Cascadian are terms that derive from the Cascade Range and may refer to:
Bioregionalism is a philosophy that suggests that political, cultural, and economic systems are more sustainable and just if they are organized around naturally defined areas called bioregions. Bioregions are defined through physical and environmental features, including watershed boundaries and soil and terrain characteristics. Bioregionalism stresses that the determination of a bioregion is also a cultural phenomenon, and emphasizes local populations, knowledge, and solutions.
A bioregion is a geographical area, on land or at sea, defined not by administrative boundaries but by distinct characteristics such as plant and animal species, ecological systems, soils and landforms, human settlements and cultures those attributes give rise to, and topographic features such as watersheds. The idea of bioregions were adopted and popularized in the mid-1970s by a school of philosophy called Bioregionalism, which includes the concept that human culture, in practice, can influence bioregional definitions. Bioregions are part of a nested series of ecological scales, generally starting with local watersheds, growing into larger river systems, then Level III or IV Ecoregions, bioregions, then biogeographical Realm, followed by the continental-scale and ultimately the biosphere.
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 Gorda plate, located beneath the Pacific Ocean off the coast of northern California, is one of the northern remnants of the Farallon plate. It is sometimes referred to as simply the southernmost portion of the neighboring Juan de Fuca plate, another Farallon remnant.
The Cascadia subduction zone is a 960 km (600 mi) fault at a convergent plate boundary, about 100–200 km (70–100 mi) off the Pacific coast, that stretches from northern Vancouver Island in Canada to Northern California in the United States. It is capable of producing 9.0+ magnitude earthquakes and tsunamis that could reach 30 m (98 ft). The Oregon Department of Emergency Management estimates shaking would last 5–7 minutes along the coast, with strength and intensity decreasing further from the epicenter. It is a very long, sloping subduction zone where the Explorer, Juan de Fuca, and Gorda plates move to the east and slide below the much larger mostly continental North American plate. The zone varies in width and lies offshore beginning near Cape Mendocino, Northern California, passing through Oregon and Washington, and terminating at about Vancouver Island in British Columbia.
The Northwestern United States, also known as the American Northwest or simply the Northwest, is an informal geographic region of the United States. The region consistently includes the states of Oregon, Washington, Idaho, Montana and Wyoming. Some sources include Southeast Alaska in the Northwest. The related but distinct term Pacific Northwest generally excludes areas from the Rockies eastward, whereas the term "Inland Northwest" excludes areas west of the Cascades.
The Mendocino fracture zone is a fracture zone and transform boundary over 4000 km long, starting off the coast of Cape Mendocino in far northern California. It runs westward from a triple junction with the San Andreas Fault and the Cascadia subduction zone for about 300 km to the southern end of the Gorda Ridge. It continues on west of its junction with the Gorda Ridge, as an inactive remnant section which extends for about 4,000 km to approximately 35°N 175°W.
The Cascadia movement is a bioregional independence movement based in the Cascadia bioregion of western North America. Potential boundaries differ, with some drawn along existing political state and provincial lines, and others drawn along larger ecological, cultural, political, and economic boundaries.
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 Coast Range Arc was a large volcanic arc system, extending from northern Washington through British Columbia and the Alaska Panhandle to southwestern Yukon. The Coast Range Arc lies along the western margin of the North American Plate in the Pacific Northwest of western North America. Although taking its name from the Coast Mountains, this term is a geologic grouping rather than a geographic one, and the Coast Range Arc extended south into the High Cascades of the Cascade Range, past the Fraser River which is the northward limit of the Cascade Range proper.
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 megaregions of the United States are eleven regions of the United States that contain two or more roughly adjacent urban metropolitan areas that, through commonality of systems, including transportation, economies, resources, and ecologies, experience blurred boundaries between the urban centers, perceive and act as if they are a continuous urban area.
The Doug flag, also referred to as the Cascadian flag or the Cascadia Doug flag and nicknamed "Old Doug" or simply "the Doug", is one of the primary symbols and an unofficial flag of the Cascadia bioregion, which roughly encompasses the U.S. states of Oregon and Washington, the Canadian province of British Columbia, and other parts of North America's Pacific Northwest. It was designed by Portland, Oregon native Alexander Baretich in the academic year of 1994–1995. It is named after the Douglas fir, featured on the flag.
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.
Bioregional mapping is a participatory approach to cartography that focuses on mapping the natural, ecological, and cultural features of a bioregion—an area defined by its natural boundaries, such as watersheds, ecosystems, and cultures that arise form a place, rather than human borders. This method highlights the interconnectedness of the region's natural systems and human communities, offering a holistic view of the landscape that integrates ecological data with cultural and historical insights.
