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 Kings River is a 132.9-mile (213.9 km) river draining the Sierra Nevada mountain range in central California in the United States. Its headwaters originate along the Sierra Crest in and around Kings Canyon National Park and form the eponymous Kings Canyon, one of the deepest river gorges in North America. The river is impounded in Pine Flat Lake before flowing into the San Joaquin Valley southeast of Fresno. With its upper and middle course in Fresno County, the Kings River diverges into multiple branches in Kings County, with some water flowing south to the old Tulare Lake bed and the rest flowing north to the San Joaquin River. However, most of the water is consumed for irrigation well upstream of either point.
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 Rogue River in southwestern Oregon in the United States flows about 215 miles (346 km) in a generally westward direction from the Cascade Range to the Pacific Ocean. Known for its salmon runs, whitewater rafting, and rugged scenery, it was one of the original eight rivers named in the Wild and Scenic Rivers Act of 1968. Beginning near Crater Lake, which occupies the caldera left by the explosive volcanic eruption and collapse of Mount Mazama, the river flows through the geologically young High Cascades and the older Western Cascades, another volcanic province. Further west, the river passes through multiple exotic terranes of the more ancient Klamath Mountains. In the Kalmiopsis Wilderness section of the Rogue basin are some of the world's best examples of rocks that form the Earth's mantle. Near the mouth of the river, the only dinosaur fragments ever discovered in Oregon were found in the Otter Point Formation, along the coast of Curry County.
Classification of indigenous peoples of the Americas is based upon cultural regions, geography, and linguistics. Anthropologists have named various cultural regions, with fluid boundaries, that are generally agreed upon with some variation. These cultural regions are broadly based upon the locations of indigenous peoples of the Americas from early European and African contact beginning in the late 15th century. When indigenous peoples have been forcibly removed by nation-states, they retain their original geographic classification. Some groups span multiple cultural regions.
The California Trail was an emigrant trail of about 1,600 mi (2,600 km) across the western half of the North American continent from Missouri River towns to what is now the state of California. After it was established, the first half of the California Trail followed the same corridor of networked river valley trails as the Oregon Trail and the Mormon Trail, namely the valleys of the Platte, North Platte, and Sweetwater rivers to Wyoming. The trail has several splits and cutoffs for alternative routes around major landforms and to different destinations, with a combined length of over 5,000 mi (8,000 km).
John Day Fossil Beds National Monument is a U.S. national monument in Wheeler and Grant counties in east-central Oregon. Located within the John Day River basin and managed by the National Park Service, the park is known for its well-preserved layers of fossil plants and mammals that lived in the region between the late Eocene, about 45 million years ago, and the late Miocene, about 5 million years ago. The monument consists of three geographically separate units: Sheep Rock, Painted Hills, and Clarno.
The Oregon School Activities Association (OSAA) is a non-profit, board-governed organization that regulates high school athletics and competitive activities via athletic conferences in the U.S. state of Oregon, providing equitable competition among its members, both public and private. The OSAA is based in Wilsonville.
The Columbia Slough is a narrow waterway, about 19 miles (31 km) long, in the floodplain of the Columbia River in the U.S. state of Oregon. From its source in the Portland suburb of Fairview, the Columbia Slough meanders west through Gresham and Portland to the Willamette River, about 1 mile (1.6 km) from the Willamette's confluence with the Columbia. It is a remnant of the historic wetlands between the mouths of the Sandy River to the east and the Willamette River to the west. Levees surround much of the main slough as well as many side sloughs, detached sloughs, and nearby lakes. Drainage district employees control water flows with pumps and floodgates. Tidal fluctuations cause reverse flow on the lower slough.
Latah Creek, also known as Hangman Creek, is a large stream in eastern Washington and north central Idaho in the United States. The creek flows northwest from the Rocky Mountains to Spokane, where it empties into the Spokane River. It drains 673 square miles (1,740 km2) in parts of Benewah and Kootenai counties in Idaho, Spokane County and a small portion of Whitman County in Washington, where over 64 percent of its watershed resides. Some major tributaries of the approximately 60-mile (97 km) creek include Little Latah Creek and Rock Creek. The average flow of the creek can range from 20 cubic feet per second (0.57 m3/s) to 20,000 cubic feet per second (570 m3/s). Latah Creek receives its name from a Nez Perce word likely meaning "fish". In 1854, the creek received another name, Hangman Creek, from a war between the Palouse Indians and white soldiers, which resulted in several Palouse being hanged alongside the creek.
Paleontology in Oregon refers to paleontological research occurring within or conducted by people from the U.S. state of Oregon. Oregon's geologic record extends back approximately 400 million years ago to the Devonian period, before which time the state's landmass was likely submerged under water. Sediment records show that Oregon remained mostly submerged until the Paleocene period. The state's earliest fossil record includes plants, corals, and conodonts. Oregon was covered by seaways and volcanic islands during the Mesozoic era. Fossils from this period include marine plants, invertebrates, ichthyosaurs, pterosaurs, and traces such as invertebrate burrows. During the Cenozoic, Oregon's climate gradually cooled and eventually yielded the environments now found in the state. The era's fossils include marine and terrestrial plants, invertebrates, fish, amphibians, turtles, birds, mammals, and traces such as eggs and animal tracks.
The Nanjemoy Formation is a geologic formation pertaining to both the Wilcox Group and the Pamunkey Group of the eastern United States, stretching across the states of Virginia, Maryland, and District of Columbia. The formation crops out east of the Appalachians and dates back to the Paleogene period. Specifically to the Ypresian stage of the Eocene epoch, about 55 to 50 Ma or Wasatchian in the NALMA classification, defined by the contemporaneous Wasatch Formation of the Pacific US coast.
The Coyote Butte Limestone (OR085) is a geologic formation in Oregon. It preserves fossils dating back to the Sakmarian to Kungurian stages of the Permian period, spanning an estimated 23 million years. The formation occurs in isolated buttes to the north; Triangulation Hill, and south; type locality and name giver Coyote Butte and Tuckers Butte, on either side of the Grindstone and Twelvemile Creeks in Crook County, Oregon.
Pleistocene 
Pliocene 
Late Miocene 
Early Miocene 
Oligocene 
Eocene 
Paleocene 
Pleistocene 
Pliocene 
Late Miocene 
Early Miocene 
Oligocene 
Eocene 
Paleocene 
Cape Sebastian Sandstone 
Chico Formation 
Hudspeth Formation 
Otter Point Formation 
Nicely & Snowshoe Formations 
Martin Bridge Limestone 
Coyote Butte Limestone 
Cape Sebastian Sandstone 
Chico Formation 
Hudspeth Formation 
Otter Point Formation 
Nicely & Snowshoe Formations 
Martin Bridge Limestone 
Coyote Butte Limestone 