The 2020 Census population count has been released at the state level. Montana, with a population of 1,085,407, gained a second seat in the US House of Representatives by a margin of 6,371 people. This margin was slightly higher than the estimate (2,500 to 4,100) Election Data Services provided in December of 2019.
This was not the smallest margin in the reapportionment process for 2020. Minnesota avoided losing a seat by only 26 people and New York lost a seat by just 89 people. Delaware (990,837) will take the designation Montana previously held of having the largest population represented by a single representative in the House of Representatives.
Montana held two seats in the House of Representatives until the reapportionment based on the 1990 census. Comparing the 1990 Census to 2020 estimates provides some insights into the population changes in Montana over the past three decades. County level population estimates based on the 2020 census have not yet been released; however, the 2020 American Community Survey estimates are available. Population growth since 1990 of over 20% occurred in 15 counties: Gallatin (131%), Broadwater (94%), Ravalli (80%), Flathead (79%), Jefferson (56%), Missoula (55%), Stillwater (51%), Madison (50%), Lewis and Clark (48%), Lake (47%), Yellowstone (44%), Sanders (40%), Mineral (37%), Carbon (35%) and Granite (30%). On the other end of spectrum, eight counties lost more than 20% of their populations; Sheridan (31%), Daniels (28%), McCone (28%), Phillips (24%), Prairie (23%), Wibaux (21%), Treasure (21%) and Garfield (20%). Five counties experienced growth of over 20,000; Gallatin (66,343), Yellowstone (49,571), Flathead (46,633), Missoula (42,943) and Lewis and Clark (22,734). Five counties experienced population loses of over 1,000; Rosebud (1,669), Sheridan (1,471), Hill (1,296), Phillips (1,244) and Deer Lodge (1,074).
In 1990, 20 Montana counties had a population of at least 10,000. The combined population of those counties was 646,398 or about 81% of Montana’s population. The population of the other 36 counties was 152,615. The 2020 population of those same 20 counties has grown to 912,581 or 84% of Montana’s population. The 2020 population of the other 36 counties was 170,016. The population of the 36 smaller counties grew 11% while the larger counties grew 44%. Two of the 20 counties (Deer Lodge and Rosebud) with a 1990 population of over 10,000 now have a population of less than 10,000. Three counties (Sanders, Carbon and Jefferson) that did not have populations of at least 10,000 in 1990 have now crossed the 10,000 mark.
Looking forward, Montana will also go through a reapportionment process for the State legislature based on the county level census results which are not yet available. Over the next 10 years, Montana will need to continue to grow at a rate roughly equal to or above the US population growth rate or the 2030 Census could result in Montana returning to a lone seat in the US House of Representatives.
