The Willamette River is a major tributary of the Columbia River, accounting for 12 to 15 percent of the Columbia's flow. The Willamette's main stem is 187 miles (301 km) long, lying entirely in northwestern Oregon in the United States. Flowing northward between the Oregon Coast Range and the Cascade Range, the river and its tributaries form the Willamette Valley, a basin that contains two-thirds of Oregon's population, including the state capital, Salem, and the state's largest city, Portland, which surrounds the Willamette's mouth at the Columbia.
The Missoula floods were cataclysmic glacial lake outburst floods that swept periodically across eastern Washington and down the Columbia River Gorge at the end of the last ice age. These floods were the result of periodic sudden ruptures of the ice dam on the Clark Fork River that created Glacial Lake Missoula. After each ice dam rupture, the waters of the lake would rush down the Clark Fork and the Columbia River, flooding much of eastern Washington and the Willamette Valley in western Oregon. After the lake drained, the ice would reform, creating Glacial Lake Missoula again.
Lake Missoula was a prehistoric proglacial lake in western Montana that existed periodically at the end of the last ice age between 15,000 and 13,000 years ago. The lake measured about 7,770 square kilometres (3,000 sq mi) and contained about 2,100 cubic kilometres (500 cu mi) of water, half the volume of Lake Michigan.
The Willamette Meteorite, officially named Willamette and originally known as Tomanowos by the Clackamas Chinook Native American tribe, is an iron-nickel meteorite found in the U.S. state of Oregon. It is the largest meteorite found in the United States and the sixth largest in the world. There was no impact crater at the discovery site; researchers believe the meteorite landed in what is now Canada or Montana, and was transported as a glacial erratic to the Willamette Valley during the Missoula Floods at the end of the last Ice Age. It has long been held sacred by indigenous peoples of the Willamette Valley, including the federally recognized Confederated Tribes of the Grand Ronde Community of Oregon (CTGRC).
Sellwood-Moreland is a neighborhood on a bluff overlooking the Willamette River in Southeast Portland, Oregon, bordering Brooklyn to the north, Eastmoreland to the east, and the city of Milwaukie to the south. The neighborhood is linked to Southwest Portland across the Willamette River by the Sellwood Bridge, the southernmost of Portland's bridges.
Northwest Industrial Area is an almost entirely industrial neighborhood in the Northwest section of Portland. According to the Portland Bureau of Planning, it "is one of the few remaining large urban industrial districts in the United States" and "one of the premier heavy industrial districts in the Pacific Northwest". It borders the neighborhoods of Linnton on the north, Forest Park on the west, the Northwest District on the south, and Cathedral Park, University Park, and Overlook across the Willamette River on the east.
The Touchet Formation or Touchet beds consist of well-bedded, coarse to fine sand and silt which overlays local bedrock composed of Neogene basalt of the Columbia River Basalt Group in south-central Washington and north-central Oregon. The beds consist of more than 40 to 62 distinct rhythmites – horizontal layers of sediment, each clearly demarcated from the layer below. These Touchet beds are often covered by windblown loess which were deposited later; the number of layers varies with location. The beds vary in thickness from 330 ft (100 m) at lower elevations where a number of layers can be found to a few extremely thin layers at the maximum elevation where they are observed.
Kerns is a neighborhood in the inner Northeast and Southeast sections of Portland, Oregon. It borders the Lloyd District and Sullivan's Gulch on the north, Laurelhurst on the east, Buckman and Sunnyside on the south, and Old Town Chinatown on the west.
Johnson Creek is a 25-mile (40 km) tributary of the Willamette River in the Portland metropolitan area of the U.S. state of Oregon. Part of the drainage basin of the Columbia River, its catchment consists of 54 square miles (140 km2) of mostly urban land occupied by about 180,000 people as of 2012. Passing through the cities of Gresham, Portland, and Milwaukie, the creek flows generally west from the foothills of the Cascade Range through sediments deposited by glacial floods on a substrate of basalt. Though polluted, it is free-flowing along its main stem and provides habitat for salmon and other migrating fish.
Tryon Creek is a 4.85-mile (7.81 km) tributary of the Willamette River in the U.S. state of Oregon. Part of the drainage basin of the Columbia River, its watershed covers about 6.5 square miles (16.8 km2) in Multnomah and Clackamas counties. The stream flows southeast from the Tualatin Mountains through the Multnomah Village neighborhood of Portland and the Tryon Creek State Natural Area to the Willamette in the city of Lake Oswego. Parks and open spaces cover about 21 percent of the watershed, while single-family homes dominate most of the remainder. The largest of the parks is the state natural area, which straddles the border between the two cities and counties.
The Alameda Ridge is a large gravel bar located in Portland, Oregon, United States. It forms a ridgeline above much of north and southeast Portland, with views of downtown and west side neighborhoods. Alameda Ridge runs through the Madison South, Roseway, Rose City Park, Beaumont-Wilshire, Alameda, and Sabin neighborhoods.
Balch Creek is a 3.5-mile (5.6 km) tributary of the Willamette River in the U.S. state of Oregon. Beginning at the crest of the Tualatin Mountains, the creek flows generally east down a canyon along Northwest Cornell Road in unincorporated Multnomah County and through the Macleay Park section of Forest Park, a large municipal park in Portland. At the lower end of the park, the stream enters a pipe and remains underground until reaching the river. Danford Balch, after whom the creek is named, settled a land claim along the creek in the mid-19th century. After murdering his son-in-law, he became the first person legally hanged in Oregon.
The Ice Age Floods National Geologic Trail is a network of routes connecting natural sites and facilities that provide interpretation of the geological consequences of the Glacial Lake Missoula floods of the last glacial period that occurred about 18,000 to 15,000 years ago. It includes sites in Washington, Oregon, Idaho, and Montana. It was designated as the first National Geologic Trail in the United States in 2009.
Lake Allison was a temporary lake in the Willamette Valley of Oregon, formed periodically by the Missoula Floods from 15,000 to 13,000 BC. The lake is the main cause of the rich and fertile soil that now characterizes the Willamette Valley.
Lake Condon was a temporary lake in the Pacific Northwest region of North America, formed periodically by the Missoula Floods from 15,000 to 13,000 BC. It was named after Oregon geologist Thomas Condon.
Mount Jumbo, also called Mount Loyola by some locals, is a mountain that overlooks the city of Missoula in the U.S. state of Montana. The mountain is northeast of the city's downtown and, in its majority, is publicly owned. In 1996, Jumbo was purchased from private landowners and protected from development. Funding for this purchase came from an open space bond, federal and non-profit agencies and thousands of local contributors. Additional land parcels have been purchased since then, increasing the easement to 1,800 acres (730 ha).
The Willamette Valley is a 150-mile (240 km) long valley in Oregon, in the Pacific Northwest region of the United States. The Willamette River flows the entire length of the valley and is surrounded by mountains on three sides: the Cascade Range to the east, the Oregon Coast Range to the west, and the Calapooya Mountains to the south.
Tanner Creek is a small tributary of the Willamette River in Portland in the U.S. state of Oregon. Named after a tannery owned by one of the city's founders, it begins in what is now the Sylvan–Highlands neighborhood in the Tualatin Mountains west of downtown. In the 19th century the creek flowed on the surface, running northeast across the city, past what later became Providence Park and into a shallow lake and wetlands in what became the Pearl District, bordering the river.
The Willamette Escarpment is an escarpment that runs along the east bank of the Willamette River in Portland, Oregon, United States. The escarpment comprises two distinct sections: a 200-acre (81 ha) North Escarpment Unit, which extends from the Fremont Bridge northwest to the St. Johns Bridge, and a 75-acre (30 ha) South Escarpment Unit, which extends from the Sellwood Bridge north to the Ross Island Bridge.
The following is a timeline of the history of Oregon in the United States of America.
