This is Montana Montana: One state with three changing regions

Montana is a single state. But in reality, there are many Montanas – some defined by variations in terrain and vegetation, others by climate and still others by land use and population density. Area economies also vary considerably from one part of Montana to the next.

From east to west, the state splits into two vastly different regions, one defined by rolling grasslands stretching across sprawling plains and the other defined by a large number of forested and interconnected mountain ranges with low-lying valleys and abundant rivers and lakes.

Between this "Eastern Plains" region and "Western Mountain" region is a third discernible transition region that connects these. The "Central Front" region extends north-by-northwest from Wyoming through the Billings area and further northwest to the Great Falls area and further into Canada.

The "Central" graphic generally shows how these three main geographic regions in Montana can be demarcated using county boundary lines. Twenty-one of the state's counties largely lie in the Western Mountain region, with another 21 in the Eastern Plains and 14 within the Central Front.

Examining recent and past population trends using these three groupings of counties for the regions helps us see how differently Montana's population varies from west to east, as well as how population is changing. The "County Population" graphic shows the number of people residing in each of these counties in 2017. Population totals for each of the counties is arrayed in the graph from highest to lowest for each of the regions, with Western Mountain counties at the left and Eastern Plains counties at the right.

Yellowstone County in the Central Front with the state's largest city, Billings, has the single biggest population among the counties, with almost 160,000 residents. Only four of Montana's counties have 100,000 residents or more, and, besides Yellowstone, three of these are located in Montana's Western Mountain region. These include Missoula County at 117,441 residents, Gallatin at 107,810, and Flathead at 100,000. Next is Cascade at 81,654, which along with Yellowstone County, contains much of the population residing along Montana's entire Central Front. Lewis and Clark is next at 67,773.

These six urban counties that contain Montana's largest cities together account for 63 percent of all state residents.

If you tally up the total number of residents in each of the three regions, the Western Mountain region has the most at more than 630,000 or 60 percent of the state total, and this has grown from 53 percent of the total more than 25 years earlier in 1990. The Central Front region has a total population of 313,000 – about half the total of the Western Mountain region. And the Eastern Plains region has a total population of less than 107,000 – only about 10 percent of the state total, down from 14 percent of the total in 1990.

The "Population Change" graphic shows the year-to-year patterns in population change for each of these three regions since 1990. Over this 27-year period, there are three discernible "spurts" in population growth in the Western Mountain region, where much of the state's growth has been concentrated.

The first was in the early '90s, largely from 1992 to 1995. This was associated with what has been described as a "sea change" in larger migration trends in the western United States, with increasing numbers of mainly U.S. residents moving from states farther to the west, south and east into Montana.

The second spurt occurred over several years just prior to the nationwide economic recession, mainly from 2004 to 2008. The third spurt in population growth is occurring now and has steadily gained strength almost each year since growth in the west hit a low in 2010. In sharp contrast the Eastern Plains region experienced years of population decline in 16 of the 27 years, with only small gains between 2009 and 2015.

Many population researchers and analysts associate growth in areas like the Western Mountain region of Montana with fundamental restructuring and change in the U.S. economy. More people are choosing to work and live in places with high qualities of life and ample area environmental amenities and recreational resources. Growth clearly also is focused mainly in and near Montana's small cities and urban areas – also reflecting fundamental changes in the state's economy. These propositions will be explored further in subsequent articles in this series.

About the author: Larry Swanson is a Ph.D. economist and regional scientist. He is director and Scott Family Senior Fellow of the O'Connor Center for the Rocky Mountain West at the University of Montana. The center is a regional studies and public education program. This is the first in a series of articles by Swanson that explore key changes occurring in Montana's economy and how these changes are shaping varying growth patterns across the state.