National Historic Site (United States)
National Historic Site is a designation for an recognized area of national historic significance in the United States. An NHS contains a single historical feature directly associated with its subject. A related but separate designation, the National Historical Park, is an area that extends beyond single properties or buildings, its resources include a mix of historic and sometimes significant natural features; as of 2018, there are 89 NHSs. Most NHPs and NHSs are managed by the National Park Service; some federally designated sites are owned by local authorities or owned, but are authorized to request assistance from the NPS as affiliated areas. One property, Grey Towers National Historic Site, is managed by the U. S. Forest Service; as of October 15, 1966, all historic areas, including NHPs and NHSs, in the NPS are automatically listed on the National Register of Historic Places. There are about 90,000 NRHP sites, the large majority of which are neither owned nor managed by the NPS. Of these, about 2,500 have been designated at the highest status as National Historic Landmark sites.
National Historic Sites are federally owned and administered properties, though some remain under private or local government ownership. There are 89 NHSs, of which 77 are official NPS units, 11 are NPS affiliated areas, 1 is managed by the US Forest Service. Derived from the Historic Sites Act of 1935, a number of NHSs were established by United States Secretaries of the Interior, but most have been authorized by acts of Congress. In 1937, the first NHS was created in Salem, Massachusetts in order to preserve and interpret the maritime history of New England and the United States. There is one International Historic Site in the US park system, a unique designation given to Saint Croix Island, Maine, on the New Brunswick border; the title, given to the site of the first permanent French settlement in America, recognizes the influence that has had on both Canada and the United States. The NPS does not distinguish among these designations in terms of their preservation or management policies. In the United States, sites are "historic", while parks are "historical".
The NPS explains that a site can be intrinsically historic, while a park is a modern legal invention. As such, a park is not itself "historic", but can be called "historical" when it contains historic resources, it is the resources. Klondike Gold Rush International Historical Park was formally established in 1998 by the United States and Canada, the year of the centennial of the gold rush the park commemorates; the park comprises Klondike Gold Rush National Historical Park in Washington and Alaska, Chilkoot Trail National Historic Site in British Columbia. It was this trail which so many prospectors took in hopes of making their fortunes in the Klondike River district of Yukon. National Historic Sites List of World Heritage Sites in North America Designation of National Park System Units
Bridger-Teton National Forest
Bridger-Teton National Forest is located in western Wyoming, United States. The forest consists of 3.4 million acres, making it the third largest National Forest outside Alaska. The forest stretches from Yellowstone National Park, along the eastern boundary of Grand Teton National Park and from there rides along the western slope of the Continental Divide to the southern end of the Wind River Range; the forest extends southward encompassing the Salt River Range and Wyoming Range mountains near the Idaho border. Located within the forest are the Gros Ventre and Teton Wildernesses, totaling 1.2 million acres. Other points of interest contained in the forest include Gannett Peak, the tallest mountain in Wyoming, the Gros Ventre landslide, one of the largest visible landslides on earth. All of the forest is in turn a part of the 20-million-acre Greater Yellowstone Ecosystem. While Gannett Peak is the highest summit in the forest, another 40 named mountains rise above 12,000 feet; the high altitudes and abundant snowfall, exceeding 600 inches at some locations, provides a constant supply of water for streams and rivers.
1,500 lakes help provide water for the Yellowstone and Green rivers, which all have their headwaters in the forest. Seven of the largest glaciers outside of Alaska are located within the forest boundaries. U. S. Route 26 and U. S. Route 287 cross over the continental divide at Togwotee Pass and enter the forest from the north, U. S. Highways 89 and 191 provide access to the forest in the vicinity of Jackson and forest lands to the south; the primary tree species include lodgepole pine, Engelmann spruce, Douglas-fir, subalpine fir and whitebark pine. Willows and sagebrush are found on the lower altitudes, while above the timberline alpine meadows are common. Threatened and endangered species found within the forest boundaries include grizzly bears, black-footed ferret and peregrine falcon. Most of the mammals that existed in the region prior to European settlement can still be found here. Elk, mule deer, bighorn sheep, coyote, marmot and cougar are but a few of the 75 species of mammals known to exist in the forest.
Four subspecies of cutthroat trout are found here including the Snake River cutthroat trout. 355 species of birds have been sighted including bald eagles, trumpeter swans, sandhill cranes and Clark's nutcrackers. Over 2,000 miles of hiking trails are located in the forest providing access into wilderness areas and interlinking with trails in Yellowstone National Park. There are several dozen vehicle accessible campgrounds that have picnic tables and tent sites as well as room in some circumstances for recreational vehicles. Nighttime temperatures can be below freezing any time of the year and mosquitos in the late spring and early summer are common. Summertime high temperatures average in the 70s and the wintertime lows can drop below -50 degrees. Bridger-Teton National Forest is an administrative combination of Bridger and Teton National Forests, amalgamated in 1973; the Bridger National Forest itself absorbed Wyoming National Forest in 1923. The Wyoming National Forest had been created as the Yellowstone Forest Reserve in 1904 renamed in 1908.
The Teton Forest Reserve was created at the same time, destined to become Teton National Forest. Ranger district offices are located in Pinedale, Big Piney, Moran and Jackson; the forest headquarters is located in Jackson. In descending order of land area the forest is located in parts of Sublette, Lincoln and Fremont counties. Granite Hot Springs Green River Wilderness areas: Bridger Wilderness Gros Ventre Wilderness Teton Wilderness Official website
The Oregon Trail is a 2,170-mile historic East–West, large-wheeled wagon route and emigrant trail in the United States that connected the Missouri River to valleys in Oregon. The eastern part of the Oregon Trail spanned part of the future state of Kansas, nearly all of what are now the states of Nebraska and Wyoming; the western half of the trail spanned most of the future states of Oregon. The Oregon Trail was laid by fur traders and trappers from about 1811 to 1840, was only passable on foot or by horseback. By 1836, when the first migrant wagon train was organized in Independence, Missouri, a wagon trail had been cleared to Fort Hall, Idaho. Wagon trails were cleared farther west, reached all the way to the Willamette Valley in Oregon, at which point what came to be called the Oregon Trail was complete as annual improvements were made in the form of bridges, cutoffs and roads, which made the trip faster and safer. From various starting points in Iowa, Missouri, or Nebraska Territory, the routes converged along the lower Platte River Valley near Fort Kearny, Nebraska Territory and led to rich farmlands west of the Rocky Mountains.
From the early to mid-1830s the Oregon Trail and its many offshoots were used by about 400,000 settlers, miners and business owners and their families. The eastern half of the trail was used by travelers on the California Trail, Mormon Trail, Bozeman Trail, before turning off to their separate destinations. Use of the trail declined as the first transcontinental railroad was completed in 1869, making the trip west faster and safer. Today, modern highways, such as Interstate 80 and Interstate 84, follow parts of the same course westward and pass through towns established to serve those using the Oregon Trail. In 1803, President Thomas Jefferson issued the following instructions to Meriwether Lewis: "The object of your mission is to explore the Missouri river, & such principal stream of it, as, by its course & communication with the waters of the Pacific Ocean, whether the Columbia, Colorado and/or other river may offer the most direct & practicable water communication across this continent, for the purposes of commerce."
Although Lewis and William Clark found a path to the Pacific Ocean, it was not until 1859 that a direct and practicable route, the Mullan Road, connected the Missouri River to the Columbia River. The first land route across what is now the United States was mapped by the Lewis and Clark Expedition between 1804 and 1806. Lewis and Clark believed they had found a practical overland route to the west coast. On the return trip in 1806, they traveled from the Columbia River to the Snake River and the Clearwater River over Lolo pass again, they traveled overland up the Blackfoot River and crossed the Continental Divide at Lewis and Clark Pass and on to the head of the Missouri River. This was a shorter and faster route than the one they followed west; this route had the disadvantages of being much too rough for wagons and controlled by the Blackfoot Indians. Though Lewis and Clark had only traveled a narrow portion of the upper Missouri River drainage and part of the Columbia River drainage, these were considered the two major rivers draining most of the Rocky Mountains, the expedition confirmed that there was no "easy" route through the northern Rocky Mountains as Jefferson had hoped.
Nonetheless, this famous expedition had mapped both the eastern and western river valleys that bookend the route of the Oregon Trail across the continental divide—they just had not located the South Pass or some of the interconnecting valleys used in the high country. They did show the way for the mountain men, who within a decade would find a better way across if it was not to be an easy way. Founded by John Jacob Astor as a subsidiary of his American Fur Company in 1810, the Pacific Fur Company operated in the Pacific Northwest in the ongoing North American fur trade. Two movements of PFC employees were planned by Astor, one detachment to be sent to the Columbia River by the Tonquin and the other overland under an expedition led by Wilson Price Hunt. Hunt and his party were to find possible supply routes and trapping territories for further fur trading posts. Upon arriving at the river in March 1811, the Tonquin crew began construction of what became Fort Astoria; the ship left supplies and men to continue work on the station and ventured north up the coast to Clayoquot Sound for a trading expedition.
While anchored there, Jonathan Thorn insulted an elder Tla-o-qui-aht, elected by the natives to negotiate a mutually satisfactory price for animal pelts. Soon after, the vessel was attacked and overwhelmed by the indigenous Clayoquot killing most of the crew except its Quinault interpreter, who told the PFC management at Fort Astoria of the destruction; the next day, the ship was blown up by surviving crew members. Under Hunt, fearing attack by the Niitsitapi, the overland expedition veered south of Lewis and Clark's route into what is now Wyoming and in the process passed across Union Pass and into Jackson Hole, Wyoming. From there they went over the Teton Range via Teton Pass and down to the Snake River into modern Idaho, they abandoned their horses at the Snake River, made dugout canoes, attempted to use the river for transport. After a few days' travel they soon discovered that steep canyon
Fossil Butte National Monument
Fossil Butte National Monument is a United States National Monument managed by the National Park Service, located 15 miles west of Kemmerer, United States. It centers on an extraordinary assemblage of Eocene Epoch animal and plant fossils associated with Fossil Lake—the smallest lake of the three great lakes which were present in what are now Wyoming and Colorado; the other two lakes were Lake Uinta. Fossil Butte National Monument was established as a national monument on October 23, 1972. Fossil Butte National Monument preserves the best paleontological record of Cenozoic aquatic communities in North America and the world, within the 50-million-year-old Green River Formation — the ancient lake bed. Fossils preserved — including fish, bats, dog-sized horses and many other species of plants and animals — suggest that the region was a low, freshwater basin when the sediments accumulated, over about a 2 million-year period. During the Eocene this portion of Wyoming was a sub-tropical lake ecosystem.
The Green River Lake System contained three ancient lakes, Fossil Lake, Lake Gosiute, Lake Uinta. These lakes covered parts of northeast Utah and northwestern Colorado. Fossil Butte is a remnant of the deposits from Fossil Lake. Fossil Lake was 40 to 50 miles long from north to south and 20 miles wide. Over the two million years that it existed, the lake varied in width. Fossil Buttes National Monument contains only 13 square miles of the 900-square-mile ancient lake; the ancient lake sediments that form the primary fossil digs is referred to as the Green River Formation. In addition to this fossil-bearing strata, a large portion of the Wasatch Formation and stream sediments, is within the national monument; the Wasatch Formation represents the shoreline ecosystem around the lake and contains fossil teeth and bone fragments of Eocene mammals. Among these are early primates and horses. Coal mining for the railroad led to the settlement of the nearby town of Wyoming; when the fossils were discovered, miners dug them up to sell to collectors.
In particular, Lee Craig sold fossils from 1897 to 1937. Commercial fossil collecting is not allowed within the National Monument, but numerous quarries on private land nearby continue to produce extraordinary fossil specimens, both for museums and for private collectors; the Fossil Butte National Monument Visitor Center features over 80 fossils and fossil casts on exhibit, including fish, a crocodile, bats, birds and plants. A 13-minute video is shown what scientists have learned. Interactive exhibits let visitors create fossil rubbings to take home, a computer program discusses fossils and the current natural history of the monument. During the summer, lab personnel prepare fossils in public. Summer activities include ranger programs, hikes and geology talks, participation in fossil quarry collections for the park. A Junior Ranger program can be completed by children aged 5–12 in 3–4 hours. A highlight is hiking 3/4 mile up the butte to the dig, where interns from the Geological Society of America talk about their excavation and let children help them flake apart sedimentary deposits to discover fish fossils and coprolites.
Fish: Asterotrygon spp, an extinct stingray Diplomystus dentatus, an extinct ray-finned fish Knightia spp, an extinct fish related to herring and sardines Seven extinct species of perch Heliobatis radians, an extinct stingray Notogoneus spp, an extinct bottom-feeding fish Crossopholis magnicaudatus, a 1-meter long predatory paddlefish Asineops squamifrons, called'mystery fish'- allocated its own family Asineopidae Two extinct species of the family Osteoglossidae Amphiplaga brachyptera, an extinct freshwater fish Two extinct species of the genus HiodonAmphibians: Aleoamphiuma tetradactylum, an extinct omnivorous salamander Aerugoamnis paulus, an extinct frogMammals: Coryphodon Onychonycteris finneyi and Icaronycteris index, bats Heptodon, an extinct tapir Apatemys chardini, a tree-dwelling mammal similar to the lemur Protorohippus, an early horse-like mammal Palaeosinopa didelphoides, an otter-like carnivore Hyopsodus wortmani'tube sheep', a small omnivore L. popoagicum, an extinct odd-toed ungulateBirds: Frigate birds Pseudocrypturus cercanaxius, an extinct shoreline bird Gallinuloides wyomingesis, an extinct land fowl Primobucco mcgrewi, an extinct roller bird Four extinct species of parrot- Cyrillavis coldurnorum, Cyrillavis olsoni, Avolatavis tenens and Tynskya eocaenaReptiles: Afairiguana, an extinct anole Boavus idelmani, a small extinct snake Bahndwivici, Afairiguana avius and Bahndwivici ammoskius, extinct lizards Baptemys wyomingenis, an extinct river turtle Echmatemys wyomingensis, an extinct pond turtle Borealosuchus wilsoni and Tsoabichi greenriverenis, extinct crocodiles Three species of soft-shell turtles- Apalone heteroglypta, Axestemys byssinus and Hummelichelys guttata Baenidae, turtlePlants: Palm trees Cattails Gyrocarpus spp Lagokarpos Lacustris, a type of distinct'winged fruit' plant Lagokarpos found in lake deposits Ailanthus confucii Platycerium, a staghorn fern Salvinia preauriculata, a water fern Lygodium kaulfussi'climbing fern' Nelumbo spp Chaneya tenuis Birthwort Soapberry Species similar to a walnutArthropods: Bechleja rostrata, an extinct species of shrimp Procambarus primaevus, an extinct species of crayfish Three unidentified species of spider Dragonflies Damselflies Crickets Other insects including bees and antsPrimary source: Dinosaur National Monument, Utah
United States National Forest
National Forest is a classification of protected and managed federal lands in the United States. National Forests are forest and woodland areas owned collectively by the American people through the federal government, managed by the United States Forest Service, a division of the United States Department of Agriculture; the National Forest System was created by the Land Revision Act of 1891, signed under the presidency of Benjamin Harrison. It was the result of concerted action by Los Angeles-area businessmen and property owners who were concerned by the harm being done to the watershed of the San Gabriel Mountains by ranchers and miners. Abbot Kinney and forester Theodore Lukens were key spokesmen for the effort. In the United States there are 155 National Forests containing 190 million acres of land; these lands comprise 8.5 percent of the total land area of the United States, an area about the size of Texas. Some 87 percent of National Forest land lies west of the Mississippi River in the mountain ranges of the Western United States.
Alaska has 12 percent of all National Forest lands. The U. S. Forest Service manages all of the United States National Grasslands, around half of the United States National Recreation Areas. There are two distinctly different types of forests within the National Forest system; those east of the Great Plains in the Midwestern and Eastern United States were acquired by the federal government since 1891, may be second growth forests. The land had long been in the private domain and sometimes logged since colonial times, but was purchased by the United States government in order to create new National Forests; those west of the Great Plains in the Western United States, though established since 1891, are on lands with ownership maintained by the federal government since the U. S. acquisition and settling of the American West. These are lands that were kept in the public domain, with the exception of inholdings and donated or exchanged private forest lands. Land management of these areas focuses on conservation, timber harvesting, livestock grazing, watershed protection and recreation.
Unlike national parks and other federal lands managed by the National Park Service, extraction of natural resources from national forests is permitted, in many cases encouraged. However, the first-designated wilderness areas, some of the largest, are on National Forest lands. There are management decision conflicts between conservationists and environmentalists, natural resource extraction companies and lobbies, over the protection and/or use of National Forest lands; these conflicts center on endangered species protection, logging of old-growth forests, intensive clear cut logging, undervalued stumpage fees, mining operations and mining claim laws, logging/mining access road-building within National Forests. Additional conflicts arise from concerns that the grasslands and forest understory are grazed by sheep, and, more rising numbers of elk and mule deer due to loss of predators. Many ski resorts and summer resorts operate on leased land in National Forests. List of U. S. National Forests United States National Grassland National Forests of the United States topics State forest National Forest Management Act of 1976 Protected areas of the United States USDA Forest Service USDA Forest Service - The First Century 100 Years of Federal Forestry
The California Trail was an emigrant trail of about 3,000 mi 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. In the present states of Wyoming and Utah, the California and Oregon trails split into several different trails or cutoffs. By 1847, two former fur trading frontier forts marked trailheads for major alternative routes through Utah and Wyoming to Northern California; the first was Jim Bridger's Fort Bridger in present-day Wyoming on the Green River, where the Mormon Trail turned southwest over the Wasatch Range to the newly established Salt Lake City, Utah. From Salt Lake the Salt Lake Cutoff went north and west of the Great Salt Lake and rejoined the California Trail in the City of Rocks in present-day Idaho.
The main Oregon and California Trails crossed the Green River on several different ferries and trails that led to or bypassed Fort Bridger and crossed over a range of hills to the Great Basin drainage of the Bear River. Just past present-day Soda Springs, both trails turned northwest, following the Portneuf River valley to the British Hudson's Bay Company's Fort Hall on the Snake River in present-day Idaho. From Fort Hall the Oregon and California trails went about 50 miles southwest along the Snake River Valley to another "parting of the ways" trail junction at the junction of the Raft and Snake rivers; the California Trail from the junction followed the Raft River to the City of Rocks in Idaho near the present Nevada-Idaho-Utah tripoint. The Salt Lake and Fort Hall routes were about the same length: about 190 miles. From the City of Rocks the trail went into the present state of Utah following the South Fork of the Junction Creek. From there the trail followed along a series of small streams, such as Thousand Springs Creek in the present state of Nevada until approaching present-day Wells, where they met the Humboldt River.
By following the crooked, meandering Humboldt River Valley west across the arid Great Basin, emigrants were able to get the water and wood they needed for themselves and their teams. The water turned alkaline as they progressed down the Humboldt, there were no trees. "Firewood" consisted of broken brush, the grass was sparse and dried out. Few travelers liked the Humboldt River Valley passage. Humboldt is not good for man nor beast... and there is not timber enough in three hundred miles of its desolate valley to make a snuff-box, or sufficient vegetation along its banks to shade a rabbit, while its waters contain the alkali to make soap for a nation. At the end of the Humboldt River, where it disappeared into the alkaline Humboldt Sink, travelers had to cross the deadly Forty Mile Desert before finding either the Truckee River or Carson River in the Carson Range and Sierra Nevada mountains that were the last major obstacles before entering Northern California. An alternative route across the present states of Utah and Nevada that bypassed both Fort Hall and the Humboldt River trails was developed in 1859.
This route, the Central Overland Route, about 280 miles shorter and more than 10 days quicker, went south of the Great Salt Lake and across the middle of present-day Utah and Nevada through a series of springs and small streams. The route went south from Salt Lake City across the Jordan River to Fairfield, Utah west-southwest past Fish Springs National Wildlife Refuge, Utah, Utah, to Ely, Nevada across Nevada to Carson City, Nevada. In addition to immigrants and migrants from the East, after 1859 the Pony Express, Overland stages and the First Transcontinental Telegraph all followed this route with minor deviations. Once in western Nevada and eastern California, the pioneers worked out several paths over the rugged Carson Range and Sierra Nevada mountains into the gold fields and cities of northern California; the main routes were the Truckee Trail to the Sacramento Valley and after about 1849 the Carson Trail route to the American River and the Placerville, California gold digging region.
Starting about 1859 the Johnson Cutoff and the Henness Pass Route across the Sierras were improved and developed. These main roads across the Sierras were both toll roads so there were funds to pay for maintenance and upkeep on the roads; these toll roads were used to carry cargo west to east from California to Nevada, as thousands of tons of supplies were needed by the gold and silver miners, etc. working on the Comstock Lode near the present Virginia City, Nevada. The Johnson Cutoff, from Placerville to Carson City along today's U. S. Route 50 in California, was used by the Pony Express year-round and in the summer by the stage lines, it was the only overland route from the East to California that could be kept open for at least horse traffic in the winter. The California Trail was used from 1845 until several years after the end of the American Civil War. After about 1848 the most popular route was the Carson Route which, while rugged, was still easier than most others and entered California in the middle of the gold fields.
The trail was heav
A wetland is a distinct ecosystem, inundated by water, either permanently or seasonally, where oxygen-free processes prevail. The primary factor that distinguishes wetlands from other land forms or water bodies is the characteristic vegetation of aquatic plants, adapted to the unique hydric soil. Wetlands play a number of functions, including water purification, water storage, processing of carbon and other nutrients, stabilization of shorelines, support of plants and animals. Wetlands are considered the most biologically diverse of all ecosystems, serving as home to a wide range of plant and animal life. Whether any individual wetland performs these functions, the degree to which it performs them, depends on characteristics of that wetland and the lands and waters near it. Methods for assessing these functions, wetland ecological health, general wetland condition have been developed in many regions and have contributed to wetland conservation by raising public awareness of the functions and the ecosystem services some wetlands provide.
Wetlands occur on every continent. The main wetland types are swamp, marsh and fen. Many peatlands are wetlands; the water in wetlands is either brackish, or saltwater. Wetlands can be non-tidal; the largest wetlands include the Amazon River basin, the West Siberian Plain, the Pantanal in South America, the Sundarbans in the Ganges-Brahmaputra delta. The UN Millennium Ecosystem Assessment determined that environmental degradation is more prominent within wetland systems than any other ecosystem on Earth. Constructed wetlands are used to treat municipal and industrial wastewater as well as stormwater runoff, they may play a role in water-sensitive urban design. A patch of land that develops pools of water after a rain storm would not be considered a "wetland" though the land is wet. Wetlands have unique characteristics: they are distinguished from other water bodies or landforms based on their water level and on the types of plants that live within them. Wetlands are characterized as having a water table that stands at or near the land surface for a long enough period each year to support aquatic plants.
A more concise definition is a community composed of hydric soil and hydrophytes. Wetlands have been described as ecotones, providing a transition between dry land and water bodies. Mitsch and Gosselink write that wetlands exist "...at the interface between terrestrial ecosystems and aquatic systems, making them inherently different from each other, yet dependent on both."In environmental decision-making, there are subsets of definitions that are agreed upon to make regulatory and policy decisions. A wetland is "an ecosystem that arises when inundation by water produces soils dominated by anaerobic and aerobic processes, which, in turn, forces the biota rooted plants, to adapt to flooding." There are four main kinds of wetlands – marsh, swamp and fen. Some experts recognize wet meadows and aquatic ecosystems as additional wetland types; the largest wetlands in the world include the swamp forests of the Amazon and the peatlands of Siberia. Under the Ramsar international wetland conservation treaty, wetlands are defined as follows: Article 1.1: "...wetlands are areas of marsh, peatland or water, whether natural or artificial, permanent or temporary, with water, static or flowing, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres."
Article 2.1: " may incorporate riparian and coastal zones adjacent to the wetlands, islands or bodies of marine water deeper than six metres at low tide lying within the wetlands." Although the general definition given above applies around the world, each county and region tends to have its own definition for legal purposes. In the United States, wetlands are defined as "those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, that under normal circumstances do support, a prevalence of vegetation adapted for life in saturated soil conditions. Wetlands include swamps, marshes and similar areas"; this definition has been used in the enforcement of the Clean Water Act. Some US states, such as Massachusetts and New York, have separate definitions that may differ from the federal government's. In the United States Code, the term wetland is defined "as land that has a predominance of hydric soils, is inundated or saturated by surface or groundwater at a frequency and duration sufficient to support a prevalence of hydrophytic vegetation adapted for life in saturated soil conditions and under normal circumstances supports a prevalence of such vegetation."
Related to this legal definitions, the term "normal circumstances" are conditions expected to occur during the wet portion of the growing season under normal climatic conditions, in the absence of significant disturbance. It is not uncommon for a wetland to be dry for long portions of the growing season. Wetlands can be dry during the dry season and abnormally dry periods during the wet season, but under normal environmental conditions the soils in a wetland will be saturated to the surface or inundated such that the soils become anaerobic, those conditions will persist through the wet portion of the growing season; the most important factor producing wetlands is flooding. The duration of flooding or prolonged soil saturation by groundwater determines whether the resulting wetland has aquatic, marsh or swamp vegetation