Idaho’s fastest growing county is a surprise

The ubiquity of Idaho growth stories is so overwhelming that they are hardly even news anymore; that’s why the official results of the 2020 census were such a surprise. The Idaho county that saw the greatest percentage change in both population and housing isn’t one of the big six counties of Ada, Bannock, Bonneville, Canyon, Kootenai and Twin Falls, which drive most of the business growth in the state.

The county with the biggest change in population and housing is one smallest in area. It’s Madison County. The county’s population grew 41% between 2010 and 2020, and housing units grew by 25.2%. The driving force behind the county’s growth is not an edgy tech company or a food production business; it’s education in the form of Idaho’s largest university.

Growth of a county

Folks on the eastern side of the state probably won’t be that surprised by this result, especially anyone who remembers what a sleepy little town Rexburg was back in 2000. In 2000, the population of the county was 27,467 and the population of Rexburg, the county seat, was 17,257.

The majority of residents were, and still are, members of the Church of Jesus Christ of Latter-day Saints; selling hard liquor was illegal and beer and wine could not be sold on Sundays. Church-affiliated Ricks College, a two-year junior college, was located on the hill above town, and the Nelson-Ricks Creamery cheese factory was still in business. Highway US-20 was not yet a limited access highway.

The sidewalks in town were rolled up at 5 p.m. every evening, and downtown was a ghost town every Sunday. Maybe that’s a slight exaggeration, but there really was only one bar in town, Miller’s Hideaway, and it closed up shop for lack of business in 2007 — an event that made national news.

In 2010, Madison County had a population of 37,536 and Rexburg had a population of 25,484. Strip malls and apartment buildings popped up on the north side of town and by the junction of State Route 33 and US-20, and big box stores moved in for the first time. In 2015, the Rexburg City Council made headlines in eastern Idaho when it legalized serving beer or wine at a restaurant on a Sunday in a contested vote.

University-driven growth

In the 1990s, Ricks College was the largest junior college in the country with an enrollment of 7,500. In 2000, Church of Jesus Christ of Latter-day Saints President Gordon B. Hinckley announced that Ricks College would transition gradually to become Brigham Young University (BYU)-Idaho.

The name change came in 2001, but it took most of the decade to build an expanded university campus. The core of the new buildings on campus was dedicated in late 2010. Today, BYU-Idaho is the largest university in the state with an enrollment of over 42,000.

With the growth of BYU-Idaho came a parallel growth in Madison County as college students, added professors and university staff members moved into the area. Farm fields on the south and west side of Rexburg became subdivisions and multiunit housing aimed at the year-round student body. US-20 became a limited-access highway, a welcome upgrade that alleviated a tourism bottleneck every summer caused by visitors heading to Yellowstone.

The influx of international students has had a transformative effect in one business sector: it’s made Rexburg a go-to place to explore an explosion of cuisine. In the past 20 years, no other business or organization has moved into Madison County that has shown the growth and impact of BYU-Idaho. The result is that Madison County has experienced the largest decadal population and housing increase in the state.

Other decadal growth numbers

The county in second place is Ada, with a 26.1% population increase between the 2010 and 2020 censuses, and a 23.5% increase in housing units. In third place is Kootenai County with a 23.7% increase in population over 10 years and an 18.3% increase in housing units. In fourth place for both population and housing is Canyon County, with an increase of 22.3% in population and 16.7% in housing units. Fifth place for population is Valley County with a 19.1% increase. Fifth place for housing growth is Jefferson County, next door to land-poor Madison County, with an increase of 16.2%.

Idaho’s population increased 17.3% between the 2010 and 2020 censuses with a housing unit increase of 12.6%.