![Idaho map counties](https://upload.wikimedia.org/wikipedia/commons/e/ec/Idaho_map_counties.svg)
The
U.S. state
In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sove ...
of
Idaho
Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyomi ...
borders six other U.S. states and one
Canadian province. The states of
Washington
Washington commonly refers to:
* Washington (state), United States
* Washington, D.C., the capital of the United States
** A metonym for the federal government of the United States
** Washington metropolitan area, the metropolitan area centered o ...
and
Oregon
Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. T ...
are to the west,
Nevada
Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...
and
Utah
Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...
are to the south, and
Montana
Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columb ...
and
Wyoming
Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...
are to the east. Idaho also shares a short border with the Canadian province of
British Columbia
British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...
to the north.
Overview
The landscape is rugged, with some of the largest unspoiled natural areas in the United States. For example, at 2.3 million acres (930,000 ha), 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
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...
state with abundant natural resources and scenic areas. The state has snow-capped mountain ranges, rapids, vast lakes and steep canyons. The waters of the
Snake River run through
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 p ...
, the deepest gorge in the United States.
Shoshone Falls
Shoshone Falls () is a waterfall in the western United States, on the Snake River in south-central Idaho, approximately northeast of the city of Twin Falls. Sometimes called the "Niagara of the West," Shoshone Falls is in height, higher than ...
falls down cliffs from a height greater than
Niagara Falls
Niagara Falls () is a group of three waterfalls at the southern end of Niagara Gorge, spanning the border between the province of Ontario in Canada and the state of New York in the United States. The largest of the three is Horseshoe Fall ...
.
By far, the most important river in Idaho is the Snake River, a major tributary of the Columbia River. The Snake River flows out from
Yellowstone
Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowston ...
in northwestern
Wyoming
Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...
through the
Snake River Plain in southern Idaho before turning north, leaving the state at
Lewiston before joining the Columbia in
Kennewick
Kennewick () is a city in Benton County in the U.S. state of Washington. It is located along the southwest bank of the Columbia River, just southeast of the confluence of the Columbia and Yakima rivers and across from the confluence of the C ...
. Other major rivers are the
Clark Fork/
Pend Oreille River
The Pend Oreille River ( ) is a tributary of the Columbia River, approximately long, in northern Idaho and northeastern Washington in the United States, as well as southeastern British Columbia in Canada. In its passage through British Columbi ...
, the
Spokane River
The Spokane River is a tributary of the Columbia River, approximately long, in northern Idaho and eastern Washington in the United States. It drains a low mountainous area east of the Columbia, passing through the Spokane Valley and the city of ...
, and, many major tributaries of the Snake River, including the
Clearwater River, the
Salmon River, the
Boise River, and the
Payette River
The Payette River () is an U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed May 3, 2011 river in southwestern Idaho and is a major tributary of the Snake River.
Its headwaters originate ...
. 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
A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as H ...
on the West Coast at 465
river mile
A river mile is a measure of distance in miles along a river from its mouth. River mile numbers begin at zero and increase further upstream. The corresponding metric unit using kilometers is the river kilometer. They are analogous to vehicle roa ...
s from the Pacific at
Astoria, Oregon.
![Grand Canyon of yellowstone](https://upload.wikimedia.org/wikipedia/commons/7/73/Grand_Canyon_of_yellowstone.jpg)
The vast majority of Idaho's population lives in the Snake River Plain, a valley running from across the entirety of southern Idaho from east to west. The valley contains the major cities of
Boise
Boise (, , ) is the capital and most populous city of the U.S. state of Idaho and is the county seat of Ada County. On the Boise River in southwestern Idaho, it is east of the Oregon border and north of the Nevada border. The downtown area' ...
,
Meridian
Meridian or a meridian line (from Latin ''meridies'' via Old French ''meridiane'', meaning “midday”) may refer to
Science
* Meridian (astronomy), imaginary circle in a plane perpendicular to the planes of the celestial equator and horizon
* ...
,
Nampa,
Caldwell,
Twin Falls,
Idaho Falls
Idaho Falls ( Shoshoni: Dembimbosaage) is a city in and the county seat of Bonneville County, Idaho, United States. It is the state's largest city outside the Boise metropolitan area. As of the 2020 census, the population of Idaho Falls was 6 ...
, and
Pocatello
Pocatello () is the county seat of and largest city in Bannock County, with a small portion on the Fort Hall Indian Reservation in neighboring Power County, in the southeastern part of the U.S. state of Idaho. It is the principal city of the P ...
. The plain served as an easy pass through the Rocky Mountains for westward-bound settlers on the
Oregon Trail
The Oregon Trail was a 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 what is now the state of Kans ...
, and many settlers chose to settle the area rather than risking the treacherous route through the
Blue Mountains and the
Cascade Range to the west. The western region of the plain is known as the
Treasure Valley
The Treasure Valley is a valley in the western United States, primarily in southwestern Idaho, where the Payette, Boise, Weiser, Malheur, Owyhee, and Burnt rivers drain into the Snake River. It includes all the lowland areas from Vale in rur ...
, bound between the
Owyhee Mountains
The Owyhee Mountains are a mountain range in Owyhee County, Idaho and Malheur County, Oregon.
Mahogany Mountain and the associated volcanic craters of the Lake Owyhee volcanic field are in the Owyhee Mountains of Oregon just east of the Owyhee R ...
to the southwest and the
Boise Mountains
The Boise Mountains are a mountain range in the U.S. state of Idaho, spanning part of Boise
Boise (, , ) is the capital and most populous city of the U.S. state of Idaho and is the county seat of Ada County. On the Boise River in southweste ...
to the northeast. The central region of the Snake River Plain is known as the
Magic Valley
The Magic Valley is a region in south-central Idaho constituting Blaine, Camas, Cassia, Gooding, Jerome, Lincoln, Minidoka, and Twin Falls counties. It is particularly associated with the agricultural region in the Snake River Plain located ...
.
Idaho's highest point is
Borah Peak
Borah Peak, also known as Mount Borah or Beauty Peak, is the highest mountain in the U.S. state of Idaho and one of the most prominent peaks in the contiguous United States. It is located in the central section of the Lost River Range, within ...
, , in the
Lost River Range
The Lost River Range is a high mountain range of the Rocky Mountains, located in Central Idaho, in the Northwestern United States.
It runs southeast for approximately from the Salmon River near the community of Challis to the Snake River Val ...
north of
Mackay Mackay may refer to:
*Clan Mackay, the Scottish clan from which the surname "MacKay" derives
Mackay may also refer to:
Places Australia
* Mackay Region, a local government area
** Mackay, Queensland, a city in the above region
*** Mackay Airpor ...
. In 1983, an earthquake there caused two fatalities.
Idaho's lowest point, , is in
Lewiston, where the
Clearwater River joins the
Snake River and continues into Washington. The
Sawtooth Range is often considered Idaho's most famous mountain range. Other mountain ranges in Idaho include the
Bitterroot Range
The Bitterroot Range is a mountain range and a subrange of the Rocky Mountains that runs along the border of Montana and Idaho in the northwestern United States. The range spans an area of and is named after the bitterroot (''Lewisia rediviva' ...
, the
White Cloud Mountains
The White Cloud Mountains are part of the Rocky Mountains of the western United States, located in central Idaho, southeast of Stanley in Custer County. The range is located within the Sawtooth National Recreation Area (SNRA) and partially within ...
, the
Lost River Range
The Lost River Range is a high mountain range of the Rocky Mountains, located in Central Idaho, in the Northwestern United States.
It runs southeast for approximately from the Salmon River near the community of Challis to the Snake River Val ...
, the
Clearwater Mountains
The Clearwater Mountains are part of the Rocky Mountains, located in the panhandle of Idaho in the Western United States. The mountains lie between the Salmon River and the Bitterroot Range and encompass an area of .
__NOTOC__ Subranges North ...
, and the
Salmon River Mountains. The only active glacier in Idaho is at Borah Peak.
Salmon-Challis National Forest is located in the east central sections of the state, with Salmon National Forest to the north and Challis National Forest to the south. The forest is in an area known as the Idaho Cobalt Belt, which consists of a long
geological formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...
of
sedimentary rock
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...
that contains some of the largest
cobalt
Cobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, p ...
deposits in the U.S.
Idaho has two
time zones
Time is the continued sequence of existence and event (philosophy), events that occurs in an apparently irreversible process, irreversible succession from the past, through the present, into the future. It is a component quantity of various me ...
, with the dividing line approximately midway between Canada and
Nevada
Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...
. Southern Idaho, including the
Boise metropolitan area,
Idaho Falls
Idaho Falls ( Shoshoni: Dembimbosaage) is a city in and the county seat of Bonneville County, Idaho, United States. It is the state's largest city outside the Boise metropolitan area. As of the 2020 census, the population of Idaho Falls was 6 ...
,
Pocatello
Pocatello () is the county seat of and largest city in Bannock County, with a small portion on the Fort Hall Indian Reservation in neighboring Power County, in the southeastern part of the U.S. state of Idaho. It is the principal city of the P ...
, and
Twin Falls, are in the
Mountain Time Zone
The Mountain Time Zone of North America keeps time by subtracting seven hours from Coordinated Universal Time (UTC) when standard time ( UTC−07:00) is in effect, and by subtracting six hours during daylight saving time ( UTC−06:00). The ...
. A legislative error ( §264) theoretically placed this region in the
Central Time Zone
The North American Central Time Zone (CT) is a time zone in parts of Canada, the United States, Mexico, Central America, some Caribbean Islands, and part of the Eastern Pacific Ocean.
Central Standard Time (CST) is six hours behind Coordina ...
, but this was corrected with a 2007 amendment. Areas north of the
Salmon River, including
Coeur d'Alene,
Moscow
Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 millio ...
,
Lewiston, and
Sandpoint, are in the
Pacific Time Zone, which contains less than a quarter of the state's population and land area.
Climate
![Köppen Climate Types Idaho](https://upload.wikimedia.org/wikipedia/commons/4/4e/K%C3%B6ppen_Climate_Types_Idaho.png)
Idaho's
climate
Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologi ...
varies widely. Although the state's western border is about from the Pacific Ocean, the maritime influence is still felt in Idaho; especially, in the winter when cloud cover,
humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present.
Humidity dep ...
, and
precipitation
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...
are at their maximum extent. This influence has a moderating effect in the winter where temperatures are not as low as would otherwise be expected for a northern state with predominantly high elevations. In the panhandle, moist air masses from the coast are released as precipitation over the
North Central Rockies forests
The North Central Rockies forests is a temperate coniferous forest ecoregion of Canada and the United States. This region overlaps in large part with the North American inland temperate rainforest and gets more rain on average than the South Ce ...
, creating the
North American inland temperate rainforest. The maritime influence is least prominent in the state's eastern part where the precipitation patterns are often reversed, with wetter summers and drier winters, and seasonal temperature differences are more extreme, showing a more semi-arid
continental climate.
Idaho can be hot, although extended periods over are rare, except for the lowest point in elevation,
Lewiston, which correspondingly sees little snow. Boise receives around of snow annually.
Hot summer days are tempered by the low relative humidity and cooler evenings during summer months since, for most of the state, the highest
diurnal difference in temperature is often in the summer. Winters can be cold, although extended periods of bitter cold weather below zero are unusual. Idaho's all-time highest temperature of was recorded at
Orofino on July 28, 1934;
the all-time lowest temperature of was recorded at
Island Park Dam
Island Park Dam is operated by the U.S. Bureau of Reclamation in Fremont County, Idaho, United States. The dam lies in Targhee National Forest near Island Park. The zoned earthfill dam was built between 1937 and 1939 as part of the Minidoka Pro ...
on January 18, 1943.
Climate data
Lakes and rivers
Protected areas
As of 2018:
National parks, reserves, monuments and historic sites
*
Salmon-Challis National Forest
*
California National Historic Trail
The California Trail was an emigrant trail of about 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 f ...
*
City of Rocks National Reserve
*
Craters of the Moon National Monument and Preserve
Craters of the Moon National Monument and Preserve is a U.S. national monument and national preserve in the Snake River Plain in central Idaho. It is along US 20 ( concurrent with US 93 and US 26), between the small towns of Arco and Carey, a ...
*
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 por ...
*
Lewis and Clark National Historic Trail
The Lewis and Clark National Historic Trail is a route across the United States commemorating the Lewis and Clark Expedition of 1804 to 1806. It is part of the National Trails System of the United States. It extends for some from Pittsburgh, Pe ...
*
Minidoka National Historic Site
Minidoka National Historic Site is a National Historic Site in the western United States. It commemorates the more than 13,000 Japanese Americans who were imprisoned at the Minidoka War Relocation Center during the Second World War.
*
Nez Perce National Historical Park
The Nez Perce National Historical Park is a United States National Historical Park comprising 38 sites located across the states of Idaho, Montana, Oregon, and Washington, which include traditional aboriginal lands of the Nez Perce people. The sit ...
*
Oregon National Historic Trail
The Oregon Trail was a 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 what is now the state of Kans ...
*
Yellowstone National Park
Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowst ...
*
Pacific Northwest National Scenic Trail
The Pacific Northwest Trail (PNT) is a 1200-mile hiking trail running from the Continental Divide in Montana to the Pacific Ocean on Washington's Olympic Coast. Along the way, the PNT crosses three national parks, seven national forests, and tw ...
National recreation areas
National wildlife refuges and Wilderness Areas
National conservation areas
*
Snake River Birds of Prey National Conservation Area
The Morley Nelson Snake River Birds of Prey National Conservation Area has one of the densest populations of nesting raptors. The National Conservation Area (NCA) is located south of Boise, Idaho along of the Snake River, and is managed by the B ...
State parks
See also
*
Climate of Oregon
*
Geography of Montana
Montana is one of the eight Mountain States, located in the north of the region known as the Western United States. It borders North Dakota and South Dakota to the east. Wyoming is to the south, Idaho is to the west and southwest, and the Canadia ...
Notes
References
{{reflist