The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises 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 miles (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 US states and a Canadian province. The fourth-largest river in the United States by volume, the Columbia has the greatest flow of any North American river entering the Pacific. The Columbia has the 36th greatest discharge of any river in the world.
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 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 latter term is also sometimes used by Washington residents to refer to the Washington section of the Cascades in addition to North Cascades, the more usual U.S. term, as in North Cascades National Park. The highest peak in the range is Mount Rainier in Washington at 14,411 feet (4,392 m).
Cascade Locks is a city in Hood River County, Oregon, United States. The city took its name from a set of locks built to improve navigation past the Cascades Rapids of the Columbia River. The U.S. federal government approved the plan for the locks in 1875, construction began in 1878, and the locks were completed on November 5, 1896. The locks were subsequently submerged in 1938, replaced by Bonneville Lock and Dam, although the city lost no land from the expansion of Lake Bonneville behind the dam some 4 miles (6 km) downstream of the city. The city population was 1,144 at the 2010 census.
Bonneville Lock and Dam consists of several run-of-the-river dam structures that together complete a span of the Columbia River between the U.S. states of Oregon and Washington at River Mile 146.1. The dam is located 40 miles (64 km) east of Portland, Oregon, in the Columbia River Gorge. The primary functions of Bonneville Lock and Dam are electrical power generation and river navigation. The dam was built and is managed by the United States Army Corps of Engineers. At the time of its construction in the 1930s it was the largest water impoundment project of its type in the nation, able to withstand flooding on an unprecedented scale. Electrical power generated at Bonneville is distributed by the Bonneville Power Administration. Bonneville Lock and Dam is named for Army Capt. Benjamin Bonneville, an early explorer credited with charting much of the Oregon Trail. The Bonneville Dam Historic District was designated a National Historic Landmark District in 1987.
Mount Adams, known by some Native American tribes as Pahto or Klickitat, is a potentially active stratovolcano in the Cascade Range. Although Adams has not erupted in more than 1,000 years, it is not considered extinct. It is the second-highest mountain in Washington, after Mount Rainier.
The 1700 Cascadia earthquake occurred along the Cascadia subduction zone on January 26, 1700, with an estimated moment magnitude of 8.7–9.2. The megathrust earthquake involved the Juan de Fuca Plate from mid-Vancouver Island, south along the Pacific Northwest coast as far as northern California. The length of the fault rupture was about 1,000 kilometers, with an average slip of 20 meters (66 ft).
The Cascades Rapids were an area of rapids along North America's Columbia River, between the U.S. states of Washington and Oregon. Through a stretch approximately 150 yards (140 m) wide, the river dropped about 40 feet (12 m) in 2 miles (3.2 km). These rapids or cascades, along with the many cascades along the Columbia River Gorge in this area of Oregon and Washington, gave rise to the name for the surrounding mountains: the Cascade Range.
The Cascadia subduction zone is a convergent plate boundary that stretches from northern Vancouver Island in Canada to Northern California in the United States. 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 Bridge of the Gods is a steel truss cantilever bridge that spans the Columbia River between Cascade Locks, Oregon, and Washington state near North Bonneville. It is approximately 40 miles (64 km) east of Portland, Oregon, and 4 miles (6.4 km) upriver from Bonneville Dam. It is a toll bridge operated by the Port of Cascade Locks.
Table Mountain is a peak rising on the north side of the Columbia River in Washington state, about 4 miles (6.4 km) north-northwest of Bonneville Dam. It is one of the most spectacular landmarks of the Columbia River Gorge. Its southeast face drops 2,400 feet (730 m) in less than one horizontal mile (1.6 km.), and is topped by an almost vertical 800-foot (240 m) cliff. Table Mountain is joined by the similar Greenleaf Peak to the northeast, and also by Hamilton Mountain to the southwest, which is lower,, but similarly steep and much closer to the Columbia. Together these peaks form an impressive group on the Washington side of the Gorge.
Eagle Creek is a creek located in Hood River County, Oregon, in the Columbia River Gorge. A tributary of the Columbia River, the creek flows for approximately 15 miles (24 km) from the Thrush Pond between Eagle Butte and Tanner Butte to its mouth near Bonneville Dam. The East Fork Eagle Creek is a major tributary that begins at Wahtum Lake and joins the main stem approximately 2/3 the way between the Thrush Pond and the Columbia River, separated by Indian Mountain.
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.
The Cascade Volcanoes are a number of volcanoes in a volcanic arc in western North America, extending from southwestern British Columbia through Washington and Oregon to Northern California, a distance of well over 700 miles (1,100 km). The arc formed due to subduction along the Cascadia subduction zone. Although taking its name from the Cascade Range, this term is a geologic grouping rather than a geographic one, and the Cascade Volcanoes extend north into the Coast Mountains, past the Fraser River which is the northward limit of the Cascade Range proper.
The history of Oregon, a U.S. state, may be considered in five eras: geologic history, inhabitation by native peoples, early exploration by Europeans, settlement by pioneers, and modern development.
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 Cascade Locks and Canal was a navigation project on the Columbia River between the U.S. states of Oregon and Washington, completed in 1896. It allowed the steamboats of the Columbia River to bypass the Cascades Rapids, and thereby opened a passage from the lower parts of the river as far as The Dalles. The locks were submerged and rendered obsolete in 1938, when the Bonneville Dam was constructed, along with a new set of locks, a short way downstream.
Greenleaf Peak is a mountain in the Cascade Range in the U.S. state of Washington, located on the north side of the Columbia River near Table Mountain, in the Columbia River Gorge. The peak lies within the Columbia River Gorge National Scenic Area near Bonneville Dam. It is 3,424 feet (1,044 m) in elevation. Botanist David Douglas climbed to the summit in September 1825, making this the first recorded mountain ascent in what is now Washington state.
Dodson is an unincorporated community in Multnomah County, Oregon, United States. It is located about 4½ miles (7.2 km) east of Multnomah Falls and one mile west of Warrendale, in the Columbia River Gorge on Interstate 84/U.S. Route 30. It is across the Columbia River from Skamania, Washington. Dodson is within the Cascade Locks ZIP code.
Warrendale is an unincorporated community in Multnomah County, Oregon, United States. It is located about a mile east of Dodson and about 3 miles (4.8 km) west of Bonneville in the Columbia River Gorge on Interstate 84/U.S. Route 30. It is across the Columbia River from Beacon Rock. The community was the site of an important salmon cannery founded in the 1870s.
Frederic Homer Balch (1861—1891) was an American author from the Pacific Northwest, best known for The Bridge of the Gods: A Romance of Indian Oregon, the only work published during his brief life. Balch was the first Northwest writer to make Native Americans major characters and the first to celebrate the Northwest landscape, its primal forest, great rivers, and volcanic mountains.
