Island Park is a city in
Fremont County,
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 ...
, United States. The city's population was 286 at the
2010 census, up from 215 in 2000. The city was incorporated by owners of the many lodges and resorts along
U.S. Route 20
U.S. Route 20 or U.S. Highway 20 (US 20) is an east–west United States Numbered Highway that stretches from the Pacific Northwest east to New England. The "0" in its route number indicates that US 20 is a major coast-to-coast route. S ...
in 1947, primarily to circumvent Idaho's liquor laws that
prohibited the sale of liquor outside of city limits. It is only wide in most locations yet, at , claims to have the longest "Main Street" in the world.
Island Park is part of the
Rexburg
Rexburg is a city in Madison County, Idaho, United States. The population was 39,409 at the 2020 census. The city is the county seat of Madison County and its largest city. Rexburg is the principal city of the Rexburg, ID Micropolitan Statist ...
Micropolitan Statistical Area.
Geography
City geography
Island Park is located at (44.4996, −111.3387),
at an
elevation
The elevation of a geographic location is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface (see Geodetic datum § Ver ...
of
above sea level, making it the highest city in Idaho.
According to the
United States Census Bureau
The United States Census Bureau (USCB), officially the Bureau of the Census, is a principal agency of the U.S. Federal Statistical System, responsible for producing data about the American people and economy. The Census Bureau is part of t ...
, the city has a total area of , of which, is land and is water.
Regional geography
The area was known as Island Park long before the -long town was incorporated. The area known as Island Park is mostly a large crater or
caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...
named the
Henry's Fork Caldera
The Henry's Fork Caldera in eastern Idaho is a caldera located in an area known as Island Park, west of Yellowstone National Park. The caldera was formed by an eruption 1.3 million years ago of the Yellowstone hotspot. The eruption distributed ...
that was created by the same
hotspot that created the earlier
Island Park Caldera
The Island Park Caldera, in the U.S. states of Idaho and Wyoming, is one of the world's largest calderas, with approximate dimensions of 80 by 65 km. Its ashfall is the source of the Huckleberry Ridge Tuff that is found from southern Calif ...
and the later
Yellowstone Caldera
The Yellowstone Caldera, sometimes referred to as the Yellowstone Supervolcano, is a volcanic caldera and supervolcano in Yellowstone National Park in the Western United States. The caldera and most of the park are located in the northwest corn ...
.
In addition to the portion which lies on the Henry's Fork Caldera, about a third of what is known as Island Park is north of the caldera, extending across Henry's Lake Flat and Henry's Lake towards the Idaho/Montana border. Henry's Lake Flat is a flat bottomed valley between high mountain ranges, with
Henrys Lake
Henrys Lake is a small, shallow alpine lake in the western United States, in eastern Idaho. Approximately in area, at in length and in width, its surface elevation is above sea level.
It is on the southwest side of the Henrys Lake Mountains ...
at the northwest end of the flats.
Mount Jefferson, south of Henry's Lake, is high and Targhee Peak, north of Henrys Lake is high. The most famous of Island Park's peaks, however, is the
Sawtell Peak
Sawtell Peak, also spelled Sawtelle Peak is a mountain in the U.S. state of Idaho. It is located in the eastern portion of the Centennial Mountains. Sawtell Peak is located in the Caribou-Targhee National Forest roughly east of Idaho's border wi ...
, south of Henrys Lake near Mount Jefferson. The peak is known for its beauty and is named for a perceived resemblance to a
Native American chief's profile while napping. The peak has also been called Chief Rains in the Face. Sawtell Peak is topped by a
FAA
The Federal Aviation Administration (FAA) is the largest transportation agency of the U.S. government and regulates all aspects of civil aviation in the country as well as over surrounding international waters. Its powers include air traffic m ...
radar dome and is visible from nearly anywhere in Island Park.
Although much smaller than either the Island Park Caldera or the Yellowstone Caldera, the Henry's Fork Caldera is still one of the largest calderas in the world and is the only large caldera in the Yellowstone region that is plainly visible. It has a nearly level wide circular floor that slopes slightly towards the southeast. The caldera floor is at about of
elevation
The elevation of a geographic location is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface (see Geodetic datum § Ver ...
with the rim generally being several hundred feet higher. The Henry's Lake Flat area, north of the caldera, is a little higher. Henry's Lake sits at about , with the flats sloping slightly southward towards the caldera.
The Island Park area is mostly forested with many meadows and grasslands. It is mostly level, but is surrounded by forested hills and high mountains in the north. The
Henrys Fork of the Snake River meanders through Island Park with its headwaters at Henry's Lake and at
Big Springs (Idaho)
Big Springs is the name of a first-magnitude spring located in Island Park, Idaho in Fremont County. The spring produces over 120 million gallons of water each day. It is a primary source of the North Fork or Henrys Fork of the Snake River. The ...
. The Henry's Fork is impounded by
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 ...
to form Island Park Reservoir outside the north rim of the caldera. In fact, the entire south bank of Island Park Reservoir is formed by the northern slope of the caldera. The Henry's Fork crosses through the caldera and then cascades off from it at
Upper and Lower Mesa Falls.
![Meadow in Island Park, Idaho](https://upload.wikimedia.org/wikipedia/commons/6/6b/Meadow_in_Island_Park%2C_Idaho.jpg)
The geography of Island Park is actually unique and distinctive. It is largely flat and it has unusually high precipitation. Island Park is at the same elevation as Teton Valley, Idaho, Jackson Hole, Wyoming, or the Centennial Valley, Montana; yet while these nearby areas are semi-arid prairie or even desert areas receiving less than of precipitation annually, Island Park is forested and green with many streams, ponds, lakes, and meadows. Island Park receives well over of precipitation annually, with parts receiving over . That is, Island Park has three times the rainfall and snowfall as nearby areas of the same elevation.
The
Snake River Plain that was also formed by the Yellowstone
hotspot aligns with the gap between the
Sierra Nevada and
Cascade mountain ranges along the
West Coast of the United States
The West Coast of the United States, also known as the Pacific Coast, Pacific states, and the western seaboard, is the coastline along which the Western United States meets the North Pacific Ocean. The term typically refers to the contiguous U.S ...
so that there is a
moisture channel that extends from the distant
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...
, between the Cascades and Sierra Nevada, through the
Rocky Mountains
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 ...
to Island Park.
This abundant precipitation in Island Park falls on the relatively level floor of the caldera, where it forms numerous meandering streams, ponds, marshes, and meadows. It also falls on the higher areas to the east along the Yellowstone Park border, where it percolates though the granular volcanic deposits to emerge as some of the largest springs in the world.
Big Springs, Buffalo River Springs, and Warm River Springs all are
1st Magnitude springs, and they form some of the crystal clear meandering streams that the area is famous for.
Demographics
2010 census
As of the
census
A census is the procedure of systematically acquiring, recording and calculating information about the members of a given population. This term is used mostly in connection with national population and housing censuses; other common censuses in ...
of 2010, there were 286 people, 122 households, and 74 families residing in the city. The
population density
Population density (in agriculture: Stock (disambiguation), standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key geographical ...
was . There were 692 housing units at an average density of . The racial makeup of the city was 96.9%
White
White is the lightest color and is achromatic (having no hue). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully reflect and scatter all the visible wavelengths of light. White o ...
, 0.7%
Native American, 1.7% from
other races
Other often refers to:
* Other (philosophy), a concept in psychology and philosophy
Other or The Other may also refer to:
Film and television
* ''The Other'' (1913 film), a German silent film directed by Max Mack
* ''The Other'' (1930 film), a ...
, and 0.7% from two or more races.
Hispanic
The term ''Hispanic'' ( es, hispano) refers to people, cultures, or countries related to Spain, the Spanish language, or Hispanidad.
The term commonly applies to countries with a cultural and historical link to Spain and to viceroyalties forme ...
or
Latino
Latino or Latinos most often refers to:
* Latino (demonym), a term used in the United States for people with cultural ties to Latin America
* Hispanic and Latino Americans in the United States
* The people or cultures of Latin America;
** Latin A ...
of any race were 6.6% of the population.
There were 122 households, of which 19.7% had children under the age of 18 living with them, 55.7% were
married couples living together, 2.5% had a female householder with no husband present, 2.5% had a male householder with no wife present, and 39.3% were non-families. 33.6% of all households were made up of individuals, and 5% had someone living alone who was 65 years of age or older. The average household size was 2.28 and the average family size was 2.97.
The median age in the city was 45 years. 19.2% of residents were under the age of 18; 6.2% were between the ages of 18 and 24; 24.4% were from 25 to 44; 34.2% were from 45 to 64; and 15.7% were 65 years of age or older. The gender makeup of the city was 53.5% male and 46.5% female.
2000 census
As of the
census
A census is the procedure of systematically acquiring, recording and calculating information about the members of a given population. This term is used mostly in connection with national population and housing censuses; other common censuses in ...
of 2000, there were 215 people, 90 households, and 57 families residing in the city. The population density was . There were 425 housing units at an average density of . The racial makeup of the city was 95.81%
White
White is the lightest color and is achromatic (having no hue). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully reflect and scatter all the visible wavelengths of light. White o ...
, 0.93%
Asian
Asian may refer to:
* Items from or related to the continent of Asia:
** Asian people, people in or descending from Asia
** Asian culture, the culture of the people from Asia
** Asian cuisine, food based on the style of food of the people from Asi ...
, 2.33% from
other races
Other often refers to:
* Other (philosophy), a concept in psychology and philosophy
Other or The Other may also refer to:
Film and television
* ''The Other'' (1913 film), a German silent film directed by Max Mack
* ''The Other'' (1930 film), a ...
, and 0.93% from two or more races.
Hispanic
The term ''Hispanic'' ( es, hispano) refers to people, cultures, or countries related to Spain, the Spanish language, or Hispanidad.
The term commonly applies to countries with a cultural and historical link to Spain and to viceroyalties forme ...
or
Latino
Latino or Latinos most often refers to:
* Latino (demonym), a term used in the United States for people with cultural ties to Latin America
* Hispanic and Latino Americans in the United States
* The people or cultures of Latin America;
** Latin A ...
of any race were 4.19% of the population.
There were 90 households, out of which 22.2% had children under the age of 18 living with them, 55.6% were
married couples living together, 6.7% had a female householder with no husband present, and 35.6% were non-families. 27.8% of all households were made up of individuals, and 2.2% had someone living alone who was 65 years of age or older. The average household size was 2.39 and the average family size was 2.93.
In the city, the population was spread out, with 19.5% under the age of 18, 11.2% from 18 to 24, 27.4% from 25 to 44, 28.4% from 45 to 64, and 13.5% who were 65 years of age or older. The median age was 42 years. For every 100 females, there were 112.9 males. For every 100 females age 18 and over, there were 119.0 males.
The median income for a household in the city was $26,250, and the median income for a family was $30,000. Males had a median income of $22,292 versus $16,250 for females. The
per capita income
Per capita income (PCI) or total income measures the average income earned per person in a given area (city, region, country, etc.) in a specified year. It is calculated by dividing the area's total income by its total population.
Per capita i ...
for the city was $15,617. About 21.0% of families and 23.9% of the population were below the
poverty line
The poverty threshold, poverty limit, poverty line or breadline is the minimum level of income deemed adequate in a particular country. The poverty line is usually calculated by estimating the total cost of one year's worth of necessities for t ...
, including 37.9% of those under the age of eighteen and none of those 65 or over.
Climate
Island Park has a
humid continental climate
A humid continental climate is a climatic region defined by Russo-German climatologist Wladimir Köppen in 1900, typified by four distinct seasons and large seasonal temperature differences, with warm to hot (and often humid) summers and freezing ...
''(Dsb)'', bordering on a
subarctic climate ''(Dsc)''. Summer days are usually warm, with nights dropping to temperatures around 40, while winters are very cold, with massive yearly snowfall averaging 215 inches (546 cm). It is the site of Idaho's lowest recorded temperature, , on January 18, 1943.
Assimilated communities
In addition to the former
unincorporated community
An unincorporated area is a region that is not governed by a local municipal corporation. Widespread unincorporated communities and areas are a distinguishing feature of the United States and Canada. Most other countries of the world either have ...
, Island Park, for which the incorporated city was named, the city either originally included, or subsequently added, several other formerly unincorporated communities:
*
Flat Rock (also known as Macks Inn)
*
Lake
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...
*
Last Chance
*
Staley Springs
Transportation
Airport
Island Park is served by
Henry's Lake Airport, which is not located within the city limits, but just west and south of the northern end of the city.
Roads
Island Park is currently served by one
U.S. Highway and one
state highway; and was previously served by another U.S. Highway and another state highway:
;Current highways
* , which runs north–south through the most of the city
* , which begins in the northern part of the city and runs northwest through the northern part of the city and on to
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 ...
;Former highways
* (1926–1981), the former routing of this highway follows the current route of US-20 this part of Idaho; in 1981 with the completion of
Interstate 15
Interstate 15 (I-15) is a major Interstate Highway in the western United States, running through Southern California and the Intermountain West. I-15 begins near the Mexican border in San Diego County and stretches north to Alberta, Cana ...
, US-191 was rerouted such that it no longer enters Idaho
* , formerly ran the length of South Big Springs Loop (from US-20 in the
Flat Rock area of the city
lso known as Macks Inneasterly to
Henrys Fork);
this route has since been decommissioned
See also
*
List of cities in Idaho
Idaho is a state located in the Western United States. According to the 2020 United States Census, Idaho is the 13th least populous state with inhabitants but the 11th largest by land area spanning of land. Idaho is divided into 44 counties an ...
References
External links
{{authority control
Cities in Idaho
Cities in Fremont County, Idaho
Rexburg, Idaho micropolitan area
1947 establishments in Idaho