Situated toward the northwestern edge of the United States, Idaho is one of the larger states in the country, and its population growth statistics are impressive as well. The last set of confirmed figures comes from the official Census of 2010 which declared that there were 1,567,582 people living in the state -- a rise of just over 20% on the numbers declared in 2000.
An updated estimate on those figures was released in 2011, and it was suggested that the population of Idaho had increased to 1,584,985, making it the 39th largest state in the US. As of the 2015 estimates, the population had increased to 1,654,930.
At a total surface area of 83,570 square miles, Idaho is the 14th biggest state in the country, and even without looking at population density figures, it’s already clear from a population of just over 1.6 million that Idaho must be a very sparsely populated state.
In fact, there are just 19 people for every square mile of land, and only six states in the US can claim a more sparsely populated landscape.
There are a number of reasons for this, mainly because parts of Idaho are inhospitable for permanent settlement. The Rocky Mountains dominate much of Idaho’s skyline and the state is also home to sprawling lakes.
The median age in Idaho is 35.7 years of age, and the state features a slight gender difference with 49.9% females and 50.1% males residing in the state.
In religious terms, the Idaho population comes in with 67% Christian based faiths, 4% non-Christian faiths, and 27% unaffiliated with any religion in particular.
Idaho was part of Oregon Territory, definitively acquired in 1846, and was included in Washington Territory upon its establishment in 1853. Idaho became a separate territory in 1863, acquired essentially its present boundaries in 1868, and was admitted as a State on July 3, 1890. Census coverage of present-day Idaho virtually began in 1870, when nearly its whole area was included.
According to the most recent ACS, the racial composition of Idaho was:
Idaho is a relatively new addition to the list of US states, and the creation of the Idaho territory took place in 1863. The first recorded Idaho population came from the US Census of 1870 when it was shown that there were just 14,999 residents.
Ten years later in 1880, those numbers had more than doubled to 32,610, and similar increases were recorded throughout the remainder of the 19th century. Idaho joined the Union in 1890, and by the time of the 1900 Census, 161,772 citizens were residing in the new state.
Those huge increases started to slow down, but continued, steady growth throughout the 20th century has taken the Idaho population of 2016 over the 1.6 million mark.
In 2005 it was claimed that Idaho was the 6th fastest growing state in the US after natural growth figures were released. In the five years following the Census of 2000, that natural growth had led to a net increase of 58,884 citizens due to 111,131 births minus 52,247 deaths and a further increase in net migration added more than 75,000 new residents.
In 2016 Idaho was still growing at an impressive 1.22% per year, putting it 11th among the 50 states in growth rate, and drawing it closer to the 38th spot in overall population, currently held by West Virginia.
Can that growth be sustained? Idaho may have the space, but geography and a harsh landscape may suggest otherwise. Estimated figures for the 2020 population are expected to surpass 1.75 million people.
Idaho is considered one of the least diverse states in the nation. In fact, it is one of just 10 states that has a predominantly white population -- or a population that is more than 90% white. The top ancestries for residents in the state include German, English and Irish. The state's percentage of African Americans ranks as 48th out of 50 states, which shows the lack of diversity within Idaho.
Idaho has been one of the fastest-growing states in the nation, increasing its population by 55% in the period from 1990 to 2010. In 2015 alone over 75,000 residents moved from other states to Idaho. However, just over 14,000 people from outside of the United States migrated to Idaho. According to 2011 data, just over 27% of children under the age of 1 were classified as belonging to racial or ethnic minority groups.
The population of counties in Idaho is balanced pretty evenly, with some counties reflecting growth in population and others posting decreasing numbers. The 2010 Census numbers were compared to estimates taken by the US Census Bureau in 2015 to get the positive and negative growth rates of all Idaho counties. These numbers show that the southwestern county of Ada had the highest growth rate, recorded as 10.36%. Neighboring county Canyon saw a growth increase of 9.54%, while Kootenai along the western border also posted a high increase of 8.23%. Other counties, including Blaine, Lincoln, and Jerome posted smaller increases in population.
As far as decreasing population, a few Idaho counties posted significant drops, with Butte County recording the highest decline of over 14%. Its neighbors Clark County and Custer County also had decreases of 10.11% and 6.26%, respectively. Other counties including Fremont, Power, and Elmore are among the other areas that had declining populations during this 5-year period.
Two or more races
Black or African American
Native Hawaiian or Pacific Islander
Average Family Size
Average Household Size
Rate of Home Ownership
Less Than 9th Grade
9th to 12th Grade
High School Graduate
High School Graduation Rate
The highest rate of high school graduation is among white people with a rate of 80.85%.
The highest rate of bachelors degrees is among asian people with a rate of 38.39%.
Other Indo-European Languages
Asian and Pacific Island Languages
89.23% of Idaho residents speak only English, while 10.77% speak other languages. The non-English language spoken by the largest group is Spanish, which is spoken by 8.07% of the population.
Overall Poverty Rate
Male Poverty Rate
Female Poverty Rate
The race most likely to be in poverty in Idaho is Islander, with 37% below the poverty level.
The race least likely to be in poverty in Idaho is White, with 12.49% below the poverty level.
The poverty rate among those that worked full-time for the past 12 months was 2.82%. Among those working part-time, it was 15.25%, and for those that did not work, the poverty rate was 16.99%.
Overall Marriage Rate
Male Marriage Rate
Female Marriage Rate
The age group where males are most likely to be married is Over 65, while the female age group most likely to be married is 35-44.
Second Gulf War
First Gulf War
World War II
Less Than 9th Grade
High School Graduate
Bachelors or Greater
Veteran Poverty Rate
Veteran Disability Rate
Labor Force Participation
Non citizens include legal permanent residents (green card holders), international students, temporary workers, humanitarian migrants, and illegal immigrants.
Born in Idaho
89.65% of Idaho residents were born in the United States, with 43.63% having been born in Idaho. 3.1% of residents are not US citizens. Of those not born in the United States, the largest percentage are from Latin America.