Discover the 8 Fastest-Growing Counties in Idaho

Written by Volia Schubiger
Updated: August 29, 2023
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In recent years, there has been a notable exodus of Americans from big cities to small-town living. Idaho is a state that has seen a serious influx of residents over the past few years. According to a study done by the University of Idaho, approximately 25% of the population in the state are newcomers. Many people have fallen in love with how beautiful Idaho is and the lower real estate prices for a home. Many first-time homeowners can purchase a bigger home in Idaho than they could anywhere else. Additionally, Idaho is one of the most beautiful states in the country. The state has a diverse landscape filled with mountains, lakes, and waterfalls. 

Discover the 8 Fastest-Growing Counties in Idaho.

So are you interested in learning about the eight fastest-growing counties in Idaho? Below, we’ll go over each county and how much the population has exploded in the past few years.

1. Ada County

Capital Building Peaks Out Between Structures in Boise

The fastest-growing county in Idaho is Ada County, which includes Boise.

©ChrisBoswell/ via Getty Images

The county with the biggest population increase is Ada County. Ada County is located in the southwestern region of the state and encompasses the city of Boise. Boise is the capital of Idaho.  Out of all of the counties in the state, Ada County happens to be the most populous one. In fact, around 26.8% of the state’s population lives in this county. Located in the heart of the high desert, this county features both desert regions as well as beautiful foothills and rivers. The area is a beautiful mix of both rural and urban areas. 

As far as population growth is concerned, this county has seen quite an increase. The population estimate in July 2020 according to the United States Census Bureau was approximately 498,260. However, this number has increased to 518,907 residents as of July 1, 2022. This is roughly over 20,000 new residents in the county in the span of two years.

2. Canyon County

Nampa Idaho

Idaho’s Canyon County features four colleges within its borders.

©Charles Knowles/

The second most populated county in Idaho happens to be Canyon County. The largest city in the county happens to be Nampa. Nampa has grown in popularity among first-time homeowners as it is quite affordable and family-friendly. The county also features four different colleges as well — Caldwell’s College of Idaho, Treasure Valley Community College, Nampa’s Northwest Nazarene University, and College of Western Idaho.  This is also an incredibly popular area for wine lovers. There are more than 74,000 acres of land dedicated to wine-growing and there are more than 15 wineries located in this county. 

The population here has seen quite an increase recently. Back in July 2012, the resident population was approximately 193,734. Since that date, the population has increased to 251,065 as of July 1, 2022.

3. Kootenai County

Coeur d'Alene, Idaho

Coeur d’Alene is located in Kootenai County, the third fastest-growing county in Idaho.

©Rotorhead 30A Productions/

Third on our list and the third most populous county is Kootenai County. Kootenai County is located in the northern part of Idaho. This county is known for having an absolutely gorgeous landscape, which is why many outdoor enthusiasts have decided to call this place home. The biggest city in this country is Coeur d’Alene. Coeur d’Alene is known for the absolutely breathtaking Lake Coeur d’Alene, where many people engage in water sports. Additionally, there are many other outdoor activities to engage in including hiking, camping, fishing, and hunting. 

This is another county in Idaho that has been seeing quite an influx of residents. The population back in July 2020 was roughly 172,790 residents. This number has increased to 183,578 residents as of July 2022. It seems that many people have fallen in love with the scenery and ample activities to enjoy in Kootenai County.

4. Bonneville County

Idaho Falls, Idaho, Temple - Building, Mormonism, Beginnings


Booneville County is another area of Idaho that has grown in popularity over the past few years. This county is located in the southeast part of the state which happens to be a part of the Upper Snake River Valley. The largest city in this county is Idaho Falls and this city itself is quite popular for a variety of reasons. For starters, this city offers tons of trails to explore and a gorgeous waterfall. There is also the eclectic Art Museum of Eastern Idaho and the Idaho Falls Zoo at Tautphaus Park which features tons of cool animals like lions, penguins, and more! With so much to do in this city, it’s no wonder that the county as a whole has grown in population size. 

Back in July 2020, the population was originally estimated at 124,716 according to the US Census Bureau. However, this number soon shot up only two years later. The population as of July 2022 was 129,496. To put this even more into perspective, the population 11 years ago in 2012 was 106,764.

5. Twin Falls County

Twin Falls, Idaho

Perrine Bridge is located in Twins Falls County and is one of the most popular spots for basejumping.

©Inbound Horizons/

As the fifth most populous county in Idaho, Twin Falls County is located in the south-central part of the state. The largest city in this county is Twin Falls. Many people love visiting and living in Twin Falls because of its ease of access to Snake River Canyon. There is also one of the most worthwhile natural attractions to witness in Twin Falls: Shoshone Falls. This stunning waterfall is 212 feet tall and 900 feet wide. It is actually one of the largest natural waterfalls in the States. 

Throughout the years, the population of this small county has only continued to grow. Just eleven years ago in 2012, the population was estimated to be around 78,550. During the last US Census conducted in 2022, the population was estimated to be around 93,696. With so many fun outdoor activities to enjoy and fun breweries and local dining, it’s no wonder this county is seeing a population increase. 

6. Bannock County

Angel, Angel Moroni, Architecture, Built Structure, Christianity

Pocatello is a mountain town in Idaho and is also home to Idaho State University.


Located in the southeastern part of Idaho is Bannock County. This county is the sixth largest in the state and houses the cities of Pocatello, Chubbuck, and McCammon. The county was first established back in 1893 and was named after the indigenous Bannock tribe that lived in the area. Pocatello is considered to be an unassuming mountain town that features lots of outdoor recreational activities and many dining and entertainment options. Idaho State University is also located in the city. 

Although a population of around 89,517 as of July 2022 may not sound like a lot, this county has only continued to grow quite a bit over the years. The population back in 2010 was only 83,020 residents. It seems that the quiet mountain life has become quite appealing for many Americans as they begin to flock to Bannock County.

7. Madison County

Rexburg Idaho

Idaho’s Madison County grew significantly by over 10,000 residents in ten years.

©Bret-Barton/ via Getty Images

Madison County is located in Idaho’s Upper Snake River Valley. This county was established back in 1913 and was actually named in honor of the fourth president of the United States, James Madison. The largest city in this county is Rexburg and this city is known for having easy access to both Grand Teton and Yellowstone National Parks. The city also has some of the best fishing and hunting in the world. People looking to be close to nature have found themselves moving to Madison County. 

Back in 2012, the census found that there was a population of only 37,662. As of the 2022 census, the population is now 54,976. This is a pretty big jump in just ten years for a small county in Idaho.

8. Bonner County

Schweitzer Idaho Ski Area Winter Snow Mountain Peaks Panoramic Aerial View

You’ll find Schweitzer Mountain, a popular ski destination, within Bonner County.

©Cascade Creatives/

Named after Edwin L. Bonner, a ferry operator, Bonner County is the last county on our list of the fastest-growing counties in Idaho. This county is located in the northern part of the state and it was named after Edwin L. Bonner because he established a ferry route on the Kootenai River where the town of Bonners Ferry is located. This ferry eventually became quite important for emigrant travel. 

As of the 2022 census, the population was found to be 51,414. This is a sharp difference when you take into account that in 2012, the population was only 40,347. As you can see, despite being a quiet rural area, this county continues to attract people here.

Summary of 8 Fastest-Growing Counties in Idaho

RankCountyOverall Population (2022 est.)
1.Ada County518,907
2.Canyon County251,065
3.Kootenai County183,578
4.Bonneville County129,496
5.Twin Falls County93,696
6.Bannock County89,517
7.Madison County54,976
8.Bonner County51,414

The photo featured at the top of this post is ©

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About the Author

Volia Schubiger is a freelance copywriter and content editor with a passion and expertise in content creation, branding, and marketing. She has a background in Broadcast Journalism & Political Science from CUNY Brooklyn College. When she's not writing she loves traveling, perusing used book stores, and hanging out with her other half.

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