The Belt Supergroup is an assemblage of fine-grained sedimentary rocks and mafic intrusive rocks of late Precambrian age. It is more than 15 kilometres thick, covers an area of some 200,000 km2, is considered to be one of the world's best-exposed and most accessible sequences of Mesoproterozoic rocks, it was named after the Big Belt Mountains in west-central Montana. It is present in western Montana and northern Idaho, with minor occurrences in northwestern Washington and western Wyoming, it extends into Canada where the equivalent rocks, which are called the Purcell Supergroup, are exposed in southeastern British Columbia and southwestern Alberta. The rocks of the Belt Supergroup contain economically significant deposits of lead, silver, copper and other metals in a number of areas, some of the Belt rocks contain fossil stromatolites. Spectacular outcrops of Belt rocks can be seen in Glacier National Park in northwestern Montana and in Waterton Lakes National Park in southwestern Alberta; the Belt Supergroup is dominated by fine-grained sedimentary rocks mudstones, fine-grained quartzose sandstones and limestones.
Most have undergone weak metamorphism to greenschist facies, as a result the mudrocks are classified as argillites and the sandstones as quartzites. The Belt Supergroup includes lesser amounts of coarser grained sandstones and conglomerates. Mafic intrusive rocks are present locally in the lower portion. Much of the sedimentation occurred between about 1450 and 1400 Ma ago. Sedimentary structures are well preserved in most of the Belt rocks despite their great age; the sedimentation is unusual in that 1) there is an abundance of fine-grained sediment and little coarser sediment, 2) there is a lack of sequence boundaries that are common in Phanerozoic sediments, 3) cyclic and rhythmic deposition occurred over long periods of time. The Belt Supergroup is noted for "Molar Tooth" structures in carbonates and various types of stromatolites. Paleogeographic reconstructions indicate that the Belt Supergroup accumulated in a fault-bounded rift basin that existed where the North American craton and another landmass were joined in a supercontinent called Columbia/Nuna.
The basin appears to have been a closed "lacustrine" environment, or at least not open marine. Depositional environments are thought to have ranged from ancient floodplains and exposed mudflats to deep water. Evidence of the basin-bounding faults exists on all sides of the Belt basin except the west, which rifted away during subsequent continemtal breakup; the identity of the joined landmass remains controversial. The Siberian craton and eastern Antarctica have all been suggested based rock ages and paleomagnetic information; the Belt Supergroup was deposited unconformably on Paleoproterozoic rocks. It reaches thicknesses of more than 15 kilometres and is present in western Montana and northern Idaho, with minor occurrences in northwestern Washington and western Wyoming; because of this widespread extent, the rock types and formation names of the Belt Supergroup vary depending upon location. In western Montana and northern Idaho the Belt is divided into the following four groups: Missoula Group - Fluvial sands and muds derived from the south.
Piegan Group - Carbonate muds alternating with laminae of clastic muds. Ravalli Group - Subaerially deposited sands and muds fluvial, derived from the southwest. Lower Belt - Heterogeneous coarse- to fine-grained clastic and carbonate rocks deep-water deposition with sediments derived from the southwest, mafic sills; the Belt Supergroup extends into Canada where the equivalent rocks are called the Purcell Supergroup, are exposed in southeastern British Columbia and southwestern Alberta. The Belt Supergroup rocks host a variety of economically significant deposits of lead, silver, copper and other metals; these include the Coeur d'Alene lead-zinc-silver mining district in Idaho, which has produced about 7,400,000 tonnes of lead, 2,900,000 tonnes of zinc, 35,600 tonnes of silver. The equivalent rocks of the Purcell Supergroup in British Columbia include the Sullivan ore body, a major producer of lead and silver. Winston and Link, Paul K. 1993, Middle Proterozoic rocks of Montana and Washington: The Belt Supergroup: in Reed.
J. Simms, P. Houston, R. Rankin, D. Link, P. Van Schmus, R. and Bickford, P. eds. Precambrian of the conterminous United States: Boulder, Geological Society of America, The Geology of North America, v. C-3, p. 487–521. "Digital Geology of Idaho - Mesoproterozoic Belt Supergroup"
Shale is a fine-grained, clastic sedimentary rock composed of mud, a mix of flakes of clay minerals and tiny fragments of other minerals quartz and calcite. Shale is characterized by breaks along thin laminae or parallel layering or bedding less than one centimeter in thickness, called fissility, it is the most common sedimentary rock. Shale exhibits varying degrees of fissility, breaking into thin layers splintery and parallel to the otherwise indistinguishable bedding plane because of the parallel orientation of clay mineral flakes. Non-fissile rocks of similar composition but made of particles smaller than 0.06 mm are described as mudstones or claystones. Rocks with similar particle sizes but with less clay and therefore grittier are siltstones. Shales are composed of clay minerals and quartz grain, are grey. Addition of variable amounts of minor constituents alters the color of the rock. Black shale results from the presence of greater than one percent carbonaceous material and indicates a reducing environment.
Black shale can be referred to as black metal. Red and green colors are indicative of ferric oxide, iron hydroxide, or micaceous minerals. Clays are the major constituent of other mudrocks; the clay minerals represented are kaolinite and illite. Clay minerals of Late Tertiary mudstones are expandable smectites whereas in older rocks in mid- to early Paleozoic shales illites predominate; the transformation of smectite to illite produces silica, calcium, magnesium and water. These released elements form authigenic quartz, calcite, ankerite and albite, all trace to minor minerals found in shales and other mudrocks. Shales and mudrocks contain 95 percent of the organic matter in all sedimentary rocks. However, this amounts to less than one percent by mass in an average shale. Black shales, which form in anoxic conditions, contain reduced free carbon along with ferrous iron and sulfur. Pyrite and amorphous iron sulfide along with carbon produce the black coloration; the process in the rock cycle which forms shale is called compaction.
The fine particles that compose shale can remain suspended in water long after the larger particles of sand have deposited. Shales are deposited in slow moving water and are found in lakes and lagoonal deposits, in river deltas, on floodplains and offshore from beach sands, they can be deposited in sedimentary basins and on the continental shelf, in deep, quiet water.'Black shales' are dark, as a result of being rich in unoxidized carbon. Common in some Paleozoic and Mesozoic strata, black shales were deposited in anoxic, reducing environments, such as in stagnant water columns; some black shales contain abundant heavy metals such as molybdenum, uranium and zinc. The enriched values are of controversial origin, having been alternatively attributed to input from hydrothermal fluids during or after sedimentation or to slow accumulation from sea water over long periods of sedimentation. Fossils, animal tracks/burrows and raindrop impact craters are sometimes preserved on shale bedding surfaces.
Shales may contain concretions consisting of pyrite, apatite, or various carbonate minerals. Shales that are subject to heat and pressure of metamorphism alter into a hard, metamorphic rock known as slate. With continued increase in metamorphic grade the sequence is phyllite schist and gneiss. Before the mid-19th century, the terms slate and schist were not distinguished. In the context of underground coal mining, shale was referred to as slate well into the 20th century. Bakken Formation Barnett Shale Bearpaw Formation Burgess Shale Marcellus Formation Mazon Creek fossil beds Oil shale – Organic-rich fine-grained sedimentary rock containing kerogen Shale gas Shale gas in the United States Wheeler Shale Wianamatta Shale Media related to Shale at Wikimedia Commons
Metamorphism is the change of minerals or geologic texture in pre-existing rocks, without the protolith melting into liquid magma. The change occurs due to heat and the introduction of chemically active fluids; the chemical components and crystal structures of the minerals making up the rock may change though the rock remains a solid. Changes at or just beneath Earth's surface due to weathering or diagenesis are not classified as metamorphism. Metamorphism occurs between diagenesis, melting; the geologists who study metamorphism are known as "metamorphic petrologists." To determine the processes underlying metamorphism, they rely on statistical mechanics and experimental petrology. Three types of metamorphism exist: contact and regional. Metamorphism produced with increasing pressure and temperature conditions is known as prograde metamorphism. Conversely, decreasing temperatures and pressure characterize retrograde metamorphism. Metamorphic rocks can change without melting. Heat causes atomic bonds to break, the atoms move and form new bonds with other atoms, creating new minerals with different chemical components or crystalline structures, or enabling recrystallization.
When pressure is applied, somewhat flattened grains that orient in the same direction have a more stable configuration. The temperature lower limit on what is considered to be a metamorphic process is considered to be 100 – 200 °C; the upper boundary of metamorphic conditions is related to the onset of melting processes in the rock. The maximum temperature for metamorphism is 700 – 900 °C, depending on the pressure and on the composition of the rock. Migmatites are rocks formed at this upper limit, which contains pods and veins of material that has started to melt but has not segregated from the refractory residue. Since the 1980s it has been recognized that rocks are dry enough and of a refractory enough composition to record without melting "ultra-high" metamorphic temperatures of 900 – 1100 °C; the metamorphic process has to be over pressure of at least 100 mega pascals but below 300 mega pascals, the depth of 100 mega pascals varies depending on what type of rock is applying pressure. Regional or Barrovian metamorphism covers large areas of continental crust associated with mountain ranges those associated with convergent tectonic plates or the roots of eroded mountains.
Conditions producing widespread regionally metamorphosed rocks occur during an orogenic event. The collision of two continental plates or island arcs with continental plates produce the extreme compressional forces required for the metamorphic changes typical of regional metamorphism; these orogenic mountains are eroded, exposing the intensely deformed rocks typical of their cores. The conditions within the subducting slab as it plunges toward the mantle in a subduction zone produce regional metamorphic effects, characterized by paired metamorphic belts; the techniques of structural geology are used to unravel the collisional history and determine the forces involved. Regional metamorphism can be described and classified into metamorphic facies or metamorphic zones of temperature/pressure conditions throughout the orogenic terrane. Contact metamorphism occurs around intrusive igneous rocks as a result of the temperature increase caused by the intrusion of magma into cooler country rock; the area surrounding the intrusion where the contact metamorphism effects are present is called the metamorphic aureole.
Contact metamorphic rocks are known as hornfels. Rocks formed by contact metamorphism may not present signs of strong deformation and are fine-grained. Contact metamorphism is greater adjacent to the intrusion and dissipates with distance from the contact; the size of the aureole depends on the heat of the intrusion, its size, the temperature difference with the wall rocks. Dikes have small aureoles with minimal metamorphism whereas large ultramafic intrusions can have thick and well-developed contact metamorphism; the metamorphic grade of an aureole is measured by the peak metamorphic mineral which forms in the aureole. This is related to the metamorphic temperatures of pelitic or aluminosilicate rocks and the minerals they form; the metamorphic grades of aureoles are sillimanite hornfels, pyroxene hornfels. Magmatic fluids coming from the intrusive rock may take part in the metamorphic reactions. An extensive addition of magmatic fluids can modify the chemistry of the affected rocks. In this case the metamorphism grades into metasomatism.
If the intruded rock is rich in carbonate the result is a skarn. Fluorine-rich magmatic waters which leave a cooling granite may form greisens within and adjacent to the contact of the granite. Metasomatic altered aureoles can localize the deposition of metallic ore minerals and thus are of economic interest. A special type of contact metamorphism, associated with fossil fuel fires, is known as pyrometamorphism. Hydrothermal metamorphism is the result of the interaction of a rock with a high-temperature fluid of variable composition; the difference in composition between an existing rock and the invading fluid triggers a set of metamorphic and metasomatic reactions. The hydrothermal fluid may be magmatic, circulating ocean water. Convective circulation of hydrothermal fluids in the ocean floor basalts produces extensive hydrothermal metamorphism adjacent to spreading centers and other submarine volcanic areas
Graptolithina is a subclass of the class Pterobranchia, the members of which are known as graptolites. These organisms are colonial animals known chiefly as fossils from the Middle Cambrian through the Lower Carboniferous. A possible early graptolite, Chaunograptus, is known from the Middle Cambrian. One analysis suggests. Studies on the tubarium of fossil and living graptolites showed similarities in the basic fusellar construction and it is considered that the group most evolved from a Rhabdopleura-like ancestor; the name graptolite comes from the Greek graptos meaning "written", lithos meaning "rock", as many graptolite fossils resemble hieroglyphs written on the rock. Linnaeus regarded them as'pictures resembling fossils' rather than true fossils, though workers supposed them to be related to the hydrozoans; the name "graptolite" originates from the genus Graptolithus, used by Linnaeus in 1735 for inorganic mineralizations and incrustations which resembled actual fossils. In 1768, in the 12th volume of Systema Naturae, he included G. sagittarius and G. scalaris a possible plant fossil and a possible graptolite.
In his 1751 Skånska Resa, he included a figure of a "fossil or graptolite of a strange kind" thought to be a type of Climacograptus. The term Graptolithina was established by Bronn in 1849 and Graptolithus was abandoned in 1954 by the ICZN. Since the 1970s, as a result of advances in electron microscopy, graptolites have been thought to be most allied to the pterobranchs, a rare group of modern marine animals belonging to the phylum Hemichordata. Comparisons are drawn with the modern hemichordates Cephalodiscus and Rhabdopleura, according to recent phylogenetic studies, rhabdopleurids are placed within the Graptolithina, they are considered an incertae sedis family. On the other hand, Cephalodiscida is considered a sister subclass of Graptolithina; some of the main differences between these two groups are that Cephalodiscida is not a colonial organism so there is not a common canal connecting all zooids, which have several arms while Graptolithina zooids have a pair. Other differences include the type of early development, the gonads, the presence or absence of gill slits, the size of the zooids.
However, in the fossil record where tubes are preserved, it is complicated to make the distinction between groups. Graptolithina includes two main orders and Graptoloidea; the latter is the most diverse, including 5 suborders. This group includes Diplograptids and Neograptids, groups that had a great development during the Ordovician. Old taxonomic classifications consider the orders Dendroidea, Camaroidea, Stolonoidea and Dithecoidea but new classifications embedded them into Graptoloidea at different taxonomic levels. Graptolites have a worldwide distribution; the preservation and gradual change over a geologic time scale of graptolites allow the fossils to be used to date strata of rocks throughout the world. They are important index fossils for dating Palaeozoic rocks as they evolved with time and formed many different species. Geologists can divide the rocks of the Silurian periods into graptolite biozones. A worldwide ice age at the end of the Ordovician eliminated most graptolites except the neograptines.
Diversification from the neograptines that survived the Ordovician glaciation began around 2 million years later. Some of the greatest extinctions that affected the group were the Hirnantian in the Ordovician and the Lundgreni in the Silurian, where the graptolites populations were reduced. In the late Ordovician extinction, a recovery event known as the Great Ordovician Diversification Event or GOBE, influenced changes in the morphology of the colonies and thecae, giving rise to new groups like the planktic Graptoloidea; each graptolite colony originates from an initial individual, called the sicular zooid, from which the subsequent zooids will develop. These zooids are housed within an organic tubular structure called a theca, coenoecium or tubarium, secreted by the glands on the cephalic shield; the composition of the tubarium is not known but different authors suggest it is made out of collagen or chitin. The tubarium has a variable number of branches or stipes and different arrangements of the theca, these features are important in the identification of graptolite fossils.
In some colonies, there are two sizes of theca, the authoteca and the bitheca, it has been suggested that this difference is due to sexual dimorphism. A mature zooid has three important regions, the preoral disc or cephalic shield, the collar and the trunk. In the collar, the mouth and anus and arms are found; as a nervous system, graptolites have a simple layer of fibers between the epidermis and the basal lamina have a collar ganglion that gives rise to several nerve branches, similar to the neural tube of chordates. All this information was inferred by the extant Rhabdopleura, however, it is likely that fossil zooids had the same morphology. An important feature in the tubarium is the fusellum, which looks like lines of growth along the tube observed as semicircular rings in a zig-zag pattern. Most of the dendritic or bushy/fan-shaped o
Haida Gwaii, is an archipelago 45–60 km off the northern Pacific coast of Canada. They are separated from the mainland to the east by the Hecate Strait. Queen Charlotte Sound lies with Vancouver Island beyond. To the north, the disputed Dixon Entrance separates Haida Gwaii from the Alexander Archipelago in the U. S. state of Alaska. Haida Gwaii consists of two main islands: Graham Island in the north and Moresby Island in the south, along with 150 smaller islands with a total landmass of 10,180 km2. Other major islands include Anthony Island, Burnaby Island, Alder Island, Kunghit Island.. Part of the Canadian province of British Columbia, the islands were known as the Queen Charlotte Islands, colloquially as "the Charlottes". On June 3, 2010, the archipelago was formally renamed by the Haida Gwaii Reconciliation Act as part of the Kunst'aa guu - Kunst'aayah Reconciliation Protocol between British Columbia and the Haida people; the islands are the heartland of the Haida Nation. Haida people have lived on the islands for 13,000 years, make up half of the population.
The Haida exercise their sovereignty over the islands through their acting government, X̱aaydaG̱a Waadlux̱an Naay, the Council of the Haida Nation, have as as 2015 hosted First Nations delegations such as the Potlatch and subsequent treaty signing between the Haida and Heiltsuk. A small number of Kaigani Haida live on the traditionally Lingít Prince of Wales Island in Alaska; some of the islands are protected under federal legislation as Gwaii Haanas National Park Reserve and Haida Heritage Site, which includes the southernmost part of Moresby Island and several adjoining islands and islets. Protected, but under provincial jurisdiction, are several provincial parks, the largest of, Naikoon Provincial Park on northeastern Graham Island; the islands are home to an abundance of wildlife, including the largest subspecies of black bear and the smallest subspecies of stoat. Black-tailed deer and raccoon are introduced species; the primary transportation links between the Islands and mainland British Columbia are through the Sandspit Airport, the Masset Airport and the BC Ferries terminal at Skidegate.
The westernmost leg of Highway 16 connects Masset and Skidegate on Graham Island, Skidegate with Prince Rupert on the mainland via regular BC Ferries service by the MV Northern Adventure. There is regular BC Ferries service between Skidegate and Alliford Bay on Moresby Island. Floatplane services connect to facilities such as the Alliford Bay Water Aerodrome and Masset Water Aerodrome; the economy is mixed, including art and natural resources logging and commercial fishing. Furthermore, service industries and government jobs provide about one-third of the jobs, tourism has become a more prominent part of the economy in recent years for fishing and tour guides, cycling and adventure tourism. Aboriginal culture tourism has been enhanced with the establishment of the Haida Heritage Centre at Kaay Ilnygaay. Public education is provided through School District 50 Haida Gwaii, which operates elementary and secondary schools in Masset, Port Clements, Queen Charlotte and Skidegate. Higher education programs are offered at the Haida Heritage Centre in partnership with the Northwest Community College, University of Northern British Columbia, with the Haida Gwaii Higher Education Society.
Publicly funded health services are provided by Northern Health, the regional health authority responsible for the northern half of the province. Haida Gwaii is served by two hospitals, The Northern Haida Gwaii Hospital and Health Centre in Masset and the Haida Gwaii Hospital in Queen Charlotte, completed in Fall 2015. Haida Gwaii has four British Columbia Ambulance stations, they are staffed by Approximately 36 casual Emergency Medical Responders, 1 Part-Time Community Paramedic based in Masset. At the time of colonial contact, the population was 30,000 people, residing in several towns and including slave populations drawn from other clans of Haida as well as from other nations, it is estimated. By 1900, only 350 people remained. Towns were abandoned as people left their homes for the towns of Skidegate and Masset, for cannery towns on the mainland, or for Vancouver Island. Today, around 4,500 people live on the islands. About 70% of the indigenous people live in two communities at Skidegate and Old Massett, with a population of about 700 each.
In total the Haida make up 45% of the population of the islands. Anthony Island and the Ninstints Haida village site were made a UNESCO World Heritage Site in 2006. Haida Gwaii is considered by archaeologists as an option for a Pacific coastal route taken by the first humans migrating to the Americas from the Bering Strait. At this time Haida Gwaii was not an island, but connected to Vancouver Island and the mainland via the now submerged continental shelf, it is unclear how people arrived on
Slate is a fine-grained, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. It is the finest grained foliated metamorphic rock. Foliation may not correspond to the original sedimentary layering, but instead is in planes perpendicular to the direction of metamorphic compression; the foliation in slate is called "slaty cleavage". It is caused by strong compression causing fine grained clay flakes to regrow in planes perpendicular to the compression; when expertly "cut" by striking parallel to the foliation, with a specialized tool in the quarry, many slates will display a property called fissility, forming smooth flat sheets of stone which have long been used for roofing, floor tiles, other purposes. Slate is grey in color when seen, en masse, covering roofs. However, slate occurs in a variety of colors from a single locality. Slate is not to schist; the word "slate" is used for certain types of object made from slate rock.
It may mean a writing slate. They were traditionally a small, smooth piece of the rock framed in wood, used with chalk as a notepad or noticeboard, for recording charges in pubs and inns; the phrases "clean slate" and "blank slate" come from this usage. Before the mid-19th century, the terms slate and schist were not distinguished. In the context of underground coal mining in the United States, the term slate was used to refer to shale well into the 20th century. For example, roof slate referred to shale above a coal seam, draw slate referred to shale that fell from the mine roof as the coal was removed. Slate is composed of the minerals quartz and muscovite or illite along with biotite, chlorite and pyrite and, less apatite, kaolinite, tourmaline, or zircon as well as feldspar; as in the purple slates of North Wales, ferrous reduction spheres form around iron nuclei, leaving a light green spotted texture. These spheres are sometimes deformed by a subsequent applied stress field to ovoids, which appear as ellipses when viewed on a cleavage plane of the specimen.
Slate can be made into roofing slates, a type of roof shingle, or more a type of roof tile, which are installed by a slater. Slate has two lines of breakability – cleavage and grain – which make it possible to split the stone into thin sheets; when broken, slate retains a natural appearance while remaining flat and easy to stack. A "slate boom" occurred in Europe from the 1870s until the first world war, allowed by the use of the steam engine in manufacturing slate tiles and improvements in road and waterway transportation systems. Slate is suitable as a roofing material as it has an low water absorption index of less than 0.4%, making the material waterproof. In fact, this natural slate, which requires only minimal processing, has the lowest embodied energy of all roofing materials. Natural slate is used by building professionals as a result of its durability. Slate is durable and can last several hundred years with little or no maintenance, its low water absorption makes it resistant to frost damage and breakage due to freezing.
Natural slate is fire resistant and energy efficient. Slate roof tiles are fixed either with nails, or with hooks as is common with Spanish slate. In the UK, fixing is with double nails onto timber battens or nailed directly onto timber sarking boards. Nails were traditionally of copper, although there are modern alloy and stainless steel alternatives. Both these methods, if used properly, provide a long-lasting weathertight roof with a lifespan of around 80–100 years; some mainland European slate suppliers suggest that using hook fixing means that: Areas of weakness on the tile are fewer since no holes have to be drilled Roofing features such as valleys and domes are easier to create since narrow tiles can be used Hook fixing is suitable in regions subject to severe weather conditions, since there is greater resistance to wind uplift, as the lower edge of the slate is secured. The metal hooks are, however and may be unsuitable for historic properties. Slate tiles are used for interior and exterior flooring, stairs and wall cladding.
Tiles are grouted along the edges. Chemical sealants are used on tiles to improve durability and appearance, increase stain resistance, reduce efflorescence, increase or reduce surface smoothness. Tiles are sold gauged, meaning that the back surface is ground for ease of installation. Slate flooring can be slippery. Slate tiles were used in 19th century UK building construction and in slate quarrying areas such as Blaenau Ffestiniog and Bethesda, Wales there are still many buildings wholly constructed of slate. Slates can be set into walls to provide a rudimentary damp-proof membrane. Small offcuts are used as shims to level floor joists. In areas where slate is plentiful it is used in pieces of various sizes for building walls and hedges, sometimes combined with other kinds of stone. In modern homes slate is used as table coasters; because it is a good electrical insulator and fireproof, it was used to construct early-20th-century electric switchboards and relay controls for large electric motors.
Fine slate can be used as a whe
Idaho is a state in the northwestern region of the United States. It borders the state of Montana to the east and northeast, Wyoming to the east and Utah to the south, Washington and Oregon to the west. To the north, it shares a small portion of the Canadian border with the province of British Columbia. With a population of 1.7 million and an area of 83,569 square miles, Idaho is the 14th largest, the 12th least populous and the 7th least densely populated of the 50 U. S. states. The state's capital and largest city is Boise. Idaho prior to European settlement was inhabited by Native American peoples, some of whom still live in the area. In the early 19th century, Idaho was considered part of the Oregon Country, an area disputed between the U. S. and the United Kingdom. It became U. S. territory with the signing of the Oregon Treaty of 1846, but a separate Idaho Territory was not organized until 1863, instead being included for periods in Oregon Territory and Washington Territory. Idaho was admitted to the Union on July 3, 1890, becoming the 43rd state.
Forming part of the Pacific Northwest, Idaho is divided into several distinct geographic and climatic regions. In the state's north, the isolated Idaho Panhandle is linked with Eastern Washington, with which it shares the Pacific Time Zone – the rest of the state uses the Mountain Time Zone; the state's south includes the Snake River Plain, while the south-east incorporates part of the Great Basin. Idaho is quite mountainous, contains several stretches of the Rocky Mountains; the United States Forest Service holds about 38 % of the most of any state. Industries significant for the state economy include manufacturing, mining and tourism. A number of science and technology firms are either headquartered in Idaho or have factories there, the state contains the Idaho National Laboratory, the country's largest Department of Energy facility. Idaho's agricultural sector supplies many products, but the state is best known for its potato crop, which comprises around one-third of the nationwide yield; the official state nickname is the "Gem State".
The name's origin remains a mystery. In the early 1860s, when the United States Congress was considering organizing a new territory in the Rocky Mountains, eccentric lobbyist George M. Willing suggested the name "Idaho", which he claimed was derived from a Shoshone language term meaning "the sun comes from the mountains" or "gem of the mountains". Willing claimed he had invented the name. Congress decided to name the area Colorado Territory when it was created in February 1861. Thinking they would get a jump on the name, locals named a community in Colorado "Idaho Springs". However, the name "Idaho" did not fall into obscurity; the same year Congress created Colorado Territory, a county called Idaho County was created in eastern Washington Territory. The county was named after a steamship named Idaho, launched on the Columbia River in 1860, it is unclear after Willing's claim was revealed. Regardless, part of Washington Territory, including Idaho County, was used to create Idaho Territory in 1863.
Despite this lack of evidence for the origin of the name, many textbooks well into the 20th century repeated as fact Willing's account the name "Idaho" derived from the Shoshone term "ee-da-how". A 1956 Idaho history textbook says:"Idaho" is a Shoshoni Indian exclamation; the word consists of three parts. The first is "Ee", which in English conveys the idea of "coming down"; the second is "dah", the Shoshoni stem or root for both "sun" and "mountain". The third syllable, "how", denotes the exclamation and stands for the same thing in Shoshoni that the exclamation mark does in the English language; the Shoshoni word is "Ee-dah-how", the Indian thought thus conveyed when translated into English means, "Behold! the sun coming down the mountain. An alternative etymology attributes the name to the Plains Apache word "ídaahę́", used in reference to The Comanche. Idaho borders six U. S. states and one Canadian province. The states of Washington and Oregon are to the west and Utah are to the south, Montana and Wyoming are to the east.
Idaho shares a short border with the Canadian province of British Columbia to the north. The landscape is rugged with some of the largest unspoiled natural areas in the United States. For example, at 2.3 million acres, the Frank Church-River of No Return Wilderness Area is the largest contiguous area of protected wilderness in the continental United States. Idaho is a Rocky Mountain state with scenic areas; the state has snow-capped mountain ranges, vast lakes and steep canyons. The waters of the Snake River rush through the deepest gorge in the United States. Shoshone Falls plunges down rugged cliffs from a height greater than Niagara Falls; the major rivers in Idaho are the Snake River, the Clark Fork/Pend Oreille River, the Clearwater River, the Salmon River. Other significant rivers include the Coeur d'Alene River, the Spokane River, the Boise River, the Payette River; the Salmon River empties into the Snake in Hells Canyon and forms the southern boundary of Nez Perce County on its north shore, of which Lewiston is the county seat.
The Port of Lewiston, at the confluence of the Clearwater and the Snake Rivers is the farthest inland seaport on the West Coast at 465 river miles from the Pacific at Astoria, Oregon. Idaho's highest point is 12,662 ft, in the Lost River Range north of Mackay. Idaho's lowest poi