Idaho (/ˈaɪdəhoʊ/ EYE-də-hoh) is a landlocked state in the Pacific Northwest and Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington and Oregon to the west; it shares a small portion of the Canada–United States border to the north, with the province of British Columbia. The state's capital and largest city is Boise. With an area of 83,569 square miles (216,440 km2), Idaho is the 14th largest state by land area. With a population of approximately 1.8 million, it ranks as the 13th least populous and the 7th least densely populated of the 50 U.S. states.
For thousands of years, and prior to European colonization, Idaho had been inhabited by native peoples. In the early 19th century, Idaho was considered part of the Oregon Country, an area of dispute between the U.S. and the British Empire. It officially became a 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 eventually admitted to the Union on July 3, 1890, becoming the 43rd state.
Forming part of the Pacific Northwest (and the associated Cascadia bioregion), Idaho is divided into several distinct geographic and climatic regions. The state's north, the relatively isolated Idaho Panhandle, is closely 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 (which has most of the population and agricultural land), and the southeast incorporates part of the Great Basin. Idaho is quite mountainous and contains several stretches of the Rocky Mountains. The United States Forest Service holds about 38% of Idaho's land, the highest proportion of any state.[7]
Industries significant for the state economy include manufacturing, agriculture, mining, forestry, and tourism. Several science and technology firms are either headquartered in Idaho or have factories there, and the state also contains the Idaho National Laboratory, which is 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."[8]
The name's origin remains a mystery.[9] In the early 1860s, when the U.S. Congress was considering organizing a new territory in the Rocky Mountains, the name "Idaho" was suggested by George M. Willing, a politician posing as an unrecognized delegate from the unofficial Jefferson Territory.[10] Willing claimed that the name was derived from a Shoshone term meaning "the sun comes from the mountains" or "gem of the mountains",[11] but it was revealed later that there was no such term and Willing claimed that he had been inspired to coin the name when he met a little girl named Ida.[12] Since the name appeared to be fabricated, the U.S. Congress ultimately decided to name the area Colorado Territory instead when it was created in February 1861, but by the time this decision was made, the town of Idaho Springs, Colorado had already been named after Willing's proposal.
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, which was launched on the Columbia River in 1860. It is unclear whether the steamship was named before or after Willing's claim was revealed. Regardless, part of Washington Territory, including Idaho County, was used to create Idaho Territory in 1863.[13] Idaho Territory would later change its boundaries to the area that became the U.S. state.[14]
Humans may have been present in the Idaho area as long as 14,500 years ago. Excavations at Wilson Butte Cave near Twin Falls in 1959 revealed evidence of human activity, including arrowheads, that rank among the oldest dated artifacts in North America. American Indian peoples predominant in the area included the Nez Percé in the north and the Northern and Western Shoshone in the south.[15]
A Late Upper Paleolithic site was identified at Cooper's Ferry in western Idaho near the town of Cottonwood by archaeologists in 2019. Based on evidence found at the site, first people lived in this area 15,300 to 16,600 years ago, predating the Beringia land bridge by about a thousand years. The discoverers emphasized that they possess similarities with tools and artifacts discovered in Japan that date from 16,000 to 13,000 years ago.[15][16] The discovery also showed that the first people might not have come to North America by land, as previously theorized. On the contrary, they probably came through the water, using a Pacific coastal route.[17]
The most parsimonious explanation we think is that people came down the Pacific Coast, and as they encountered the mouth of the Columbia River, they essentially found an off-ramp from this coastal migration and also found their first viable interior route to the areas that are south of the ice sheet.[16]
An early presence of French-Canadian trappers is visible in names and toponyms: Nez Percé, Cœur d'Alène, Boisé, Payette. Some of these names appeared prior to the Lewis and Clark and Astorian expeditions, which included significant numbers of French and Métis guides recruited for their familiarity with the terrain.[citation needed]
Idaho, as part of the Oregon Country, was claimed by both the United States and Great Britain until the United States gained undisputed jurisdiction in 1846. From 1843 to 1859, present-day Idaho was under the de facto jurisdiction of the Provisional Government of Oregon. When Oregon became a state in 1859, what is now Idaho was situated in what remained of the original Oregon Territory, designated as the Washington Territory.
Between 1849 and the creation of the Idaho Territory in 1863, parts of present-day Idaho were included in the Oregon, Washington, and Dakota Territories. The new Idaho territory included present-day Idaho, Montana, and most of Wyoming. The Lewis and Clark expedition crossed Idaho in 1805 on the way to the Pacific, and in 1806, on the return trip, largely following the Clearwater River in both directions. The first non-indigenous settlement was Kullyspell House, established on the shore of Lake Pend Oreille in 1809 by David Thompson of the North West Company for fur trading.[18][19] In 1812 Donald Mackenzie, working for the Pacific Fur Company at the time, established a post on the lower Clearwater River near present-day Lewiston. This post, known as "MacKenzie's Post" or "Clearwater", operated until the Pacific Fur Company was bought out by the North West Company in 1813, after which the post was abandoned.[20][21] The first organized non-indigenous communities within the present borders of Idaho were established by Mormon pioneers in 1860.[22]