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Snake–Columbia Shrub Steppe
The Snake–Columbia shrub steppe is an ecoregion defined by the World Wide Fund for Nature (WWF). This ecoregion receives little precipitation because it is within the rain shadow of the Cascade Range. It takes in a western portion of the Columbia Basin in Washington, and extends south along the Deschutes River Basin, expanding to cover most of southeast Oregon including the Oregon Lakes region. This ecoregion reaches south from Oregon into northern Nevada and the northeast corner of California. It also connects east onto the Snake River Plain, which it follows east from Hells Canyon to the continental divide in eastern Idaho. Information about this ecoregion is covered by two articles that follow the ecoregion definitions of the United States Environmental Protection Agency: * Columbia Plateau (ecoregion) * Snake River Plain (ecoregion) See also *List of ecoregions in the United States (WWF) The following is a list of ecoregions in the United States as identified by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hagerman Fossil Beds National Monument
Hagerman Fossil Beds National Monument near Hagerman, Idaho, contains the largest concentration of Hagerman horse fossils in North America. The fossil horses for which the monument is famous have been found in only one locale in the northern portion of the monument called the Hagerman Horse Quarry. The monument is internationally significant because it protects the world's richest known fossil deposits from the late Pliocene epoch, 3.5 million years ago. These plants and animals represent the last glimpse of that time that existed before the Ice Age, and the earliest appearances of modern flora and fauna. This is also significant because the fossils present during this period of the Pliocene represent species which were alive during the early stages in the evolution of humans, albeit on a different continent. The fossil beds were designated a National Natural Landmark in 1975. Notable fossils * Hagerman horse, ''Equus simplicidens'', formerly known as ''Plesippus shoshonensis'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold Semi-arid Climate
A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-arid climates, depending on variables such as temperature, and they give rise to different biomes. Defining attributes of semi-arid climates A more precise definition is given by the Köppen climate classification, which treats steppe climates (''BSk'' and ''BSh'') as intermediates between desert climates (BW) and humid climates (A, C, D) in ecological characteristics and agricultural potential. Semi-arid climates tend to support short, thorny or scrubby vegetation and are usually dominated by either grasses or shrubs as it usually can't support forests. To determine if a location has a semi-arid climate, the precipitation threshold must first be determined. The method used to find the precipitation threshold (in millimeters): *multiply ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecoregions Of The United States ...
Lists of ecoregions in the United States may refer to: * List of ecoregions in the United States (EPA), United States Environmental Protection Agency system * List of ecoregions in the United States (WWF), World Wildlife Fund system {{list of lists, environment Ecoregions An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Ecoregions In The United States (WWF)
The following is a list of ecoregions in the United States as identified by the World Wide Fund for Nature (WWF). The United States is a megadiverse country with a high level of endemism across a wide variety of ecosystems. Terrestrial ecoregions The United States is unique among countries in that its terrestrial ecoregions span three biogeographic realms: the Nearctic, Neotropical, and Oceanian realms. 50 states Alaska is the most biodiverse state with 15 ecoregions across 3 biomes in the same realm. California comes in a close second with 13 ecoregions across 4 biomes in the same realm. By contrast, Rhode Island is the least biodiverse with just one ecoregion - the Northeastern coastal forests - encompassing the entire state. The terrestrial ecoregions of the 50 states of the United States are as follows: 5 inhabited territories The ecoregions of the 5 inhabited territories of the United States are as follows: Marine ecoregions The marine ecoregions of the 50 states of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snake River Plain (ecoregion)
The Snake River Plain ecoregion is a Level III ecoregion designated by the United States Environmental Protection Agency (EPA) in the U.S. states of Idaho and Oregon. It follows the Snake River across Idaho, stretching roughly from the Wyoming border to Eastern Oregon in the xeric intermontane west. Characterized by plains and low hills, it is considerably lower and less rugged than surrounding ecoregions. Many of the alluvial valleys bordering the Snake River are used for agriculture. Where irrigation water and soil depth are sufficient, sugar beets, potatoes, alfalfa, small grains, and vegetables are grown. Elsewhere, livestock grazing is widespread. Cattle feedlots and dairy operations are found locally. Potential natural vegetation is mostly sagebrush steppe, but barren lava fields and saltbush-greasewood associations also occur. Streams generally have lower gradients, are warmer, and have finer grained substrates than do streams in the montane ecoregions. Natural fish asse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columbia Plateau (ecoregion)
The Columbia Plateau ecoregion is a Level III ecoregion designated by the United States Environmental Protection Agency (EPA) encompassing approximately of land within the U.S. states of Washington, Oregon, and Idaho. The ecoregion extends across a wide swath of the Columbia River Basin from The Dalles, Oregon to Lewiston, Idaho to Okanogan, Washington near the Canada–US border. It includes nearly of the Columbia River, as well as the lower reaches of major tributaries such as the Snake and Yakima rivers and the associated drainage basins. It is named for the Columbia River Plateau, a flood basalt plateau formed by the Columbia River Basalt Group during the late Miocene and early Pliocene. The arid sagebrush steppe and grasslands of the region are flanked by moister, predominantly forested, mountainous ecoregions on all sides. The underlying basalt is up to thick and partially covered by thick loess deposits. Where precipitation amounts are sufficient, the deep loess soils h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Environmental Protection Agency
The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it began operation on December 2, 1970, after Nixon signed an executive order. The order establishing the EPA was ratified by committee hearings in the House and Senate. The agency is led by its administrator, who is appointed by the president and approved by the Senate. The current administrator is Michael S. Regan. The EPA is not a Cabinet department, but the administrator is normally given cabinet rank. The EPA has its headquarters in Washington, D.C., regional offices for each of the agency's ten regions and 27 laboratories. The agency conducts environmental assessment, research, and education. It has the responsibility of maintaining and enforcing national standards under a variety of environmental laws, in consultation with state, tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continental Divide
A continental divide is a drainage divide on a continent such that the drainage basin on one side of the divide feeds into one ocean or sea, and the basin on the other side either feeds into a different ocean or sea, or else is endorheic, not connected to the open sea. Every continent on earth except Antarctica (which has no known significant, definable free-flowing surface rivers) has at least one continental drainage divide; islands, even small ones like Killiniq Island on the Labrador Sea in Canada, may also host part of a continental divide or have their own island-spanning divide. The endpoints of a continental divide may be coastlines of gulfs, seas or oceans, the boundary of an endorheic basin, or another continental divide. One case, the Great Basin Divide, is a closed loop around an endoreic basin. The endpoints where a continental divide meets the coast are not always definite since the exact border between adjacent bodies of water is usually not clearly defined. The I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hells Canyon
Hells Canyon is a canyon in the Western United States, located along the border of eastern Oregon, a small section of eastern Washington and western Idaho. It is part of the Hells Canyon National Recreation Area which is also located in part of the Wallowa-Whitman National Forest. It is North America's deepest river gorge at . Notably, Hells Canyon runs deeper than the better-known Grand Canyon in Arizona. The canyon was carved by the waters of the Snake River, which flows more than below the canyon's west rim on the Oregon side and below the peaks of Idaho's Seven Devils Mountains to the east. This area includes of wilderness. Most of the area is inaccessible by road. Geology The geologic history of the rocks of Hells Canyon began 300 million years ago with an arc of volcanoes that emerged from the waters of the Pacific Ocean. Over millions of years, the volcanoes subsided and limestone built up on the underwater platforms. The basins between them were filled wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snake River Plain
image:Snake River view near Twin Falls, Idaho.jpg, The Snake River cutting through the plain leaves many canyons and Canyon#List of gorges, gorges, such as this one near Twin Falls, Idaho The Snake River Plain is a geology, geologic feature located primarily within the U.S. state of Idaho. It stretches about westward from northwest of the state of Wyoming to the Idaho-Oregon border. The plain is a wide, flat bow-shaped depression and covers about a quarter of Idaho. Three major volcanic buttes dot the plain east of Arco, Idaho, Arco, the largest being Big Southern Butte. Most of Idaho's major cities are in the Snake River Plain, as is much of its agricultural land. Geology The Snake River Plain can be divided into three sections: western, central, and eastern. The western Snake River Plain is a large tectonic graben or rift valley filled with several kilometers of lacustrine (lake) sediments; the sediments are underlain by rhyolite and basalt, and overlain by basalt. The w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oregon Lakes
Oregon Lakes is a freshwater ecoregion in the western United States. It includes several closed basins in southern-central Oregon and adjacent parts of California and Nevada, including the Harney Basin, Warner Valley, and the basins of Lake Abert and Summer Lake."Oregon Lakes". Freshwater Ecoregions of the World. Accessed 18 September 2021/ref> Geography The ecoregion includes several closed, or endorheic, basins. The ecoregions's streams empty into alkaline lakes or onto playas. The ecoregion is bounded on the north and east by the Columbia River basin, on the west by the upper basin of the Klamath River, on the southwest by the upper Sacramento River watershed, and on the south and southeast by the closed Lahontan Basin.Howard, J., and C. Revenga (2009). "California’s freshwater biodiversity in a continental context". Science for Conservation Technical Brief Series. The Nature Conservancy of California. San Francisco, CA. 29 pp + Appendices. Accessed 18 September 2021/ref> Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deschutes River (Oregon)
The Deschutes River in central Oregon is a major tributary of the Columbia River. The river provides much of the drainage on the eastern side of the Cascade Range in Oregon, gathering many of the tributaries that descend from the drier, eastern flank of the mountains. The Deschutes provided an important route to and from the Columbia for Native Americans for thousands of years, and then in the 19th century for pioneers on the Oregon Trail. The river flows mostly through rugged and arid country, and its valley provides a cultural heart for central Oregon. Today the river supplies water for irrigation and is popular in the summer for whitewater rafting and fishing. The river flows generally north, as do several other large Oregon tributaries of the Columbia River, including the Willamette and John Day. Course The headwaters of the Deschutes River are at Little Lava Lake, a natural lake in the Cascade Range approximately northwest of the city of La Pine. The river flows s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
