# Custer County, Montana

Custer County is a county located in the southeast part of the U.S. state of Montana. As of the 2020 U.S. census, the population was 11,867. Its county seat and largest town is Miles City. The county was established after the end of the American Civil War (1861-1865), on June 2, 1865, as one of the nine original counties of the new western federal Territory of Montana, which had been formed the previous May of 1864 by the United States Congress, with the approval of 16th President Abraham Lincoln (1809-1865, served 1861-1865). It was originally named Big Horn County of the old Montana Territory, and was renamed on February 16, 1877, in honor of Lieutenant Colonel George Armstrong Custer (1839-1876), commander of the famous 7th Cavalry Regiment of the United States Army, recently massacred and killed in the nearby Battle of the Little Bighorn, in the later portion of the American Indian Wars, the year before in June 1876.

## Geography

According to the United States Census Bureau, the county has a total area of 3,793 square miles (9,820 km$^2$), of which 3,783 square miles (9,800 km$^2$) is land and 9.9 square miles (26 km$^2$) (0.3%) is water.

### Climate

According to the Köppen Climate Classification system, Custer County has a mostly cold semi-arid climate, abbreviated "BSk" on climate maps.
Climate data for Mizpah, Montana, 1991—2020 normals, extremes 1960—present :
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Record high °F (°C) | 69 (21) | 73 (23) | 85 (29) | 92 (33) | 101 (38) | 111 (44) | 112 (44) | 110 (43) | 106 (41) | 96 (36) | 80 (27) | 70 (21) | 112 (44) |
| Mean maximum °F (°C) | 51.6 (10.9) | 56.3 (13.5) | 71.9 (22.2) | 81.3 (27.4) | 87.2 (30.7) | 95.8 (35.4) | 102.5 (39.2) | 101.5 (38.6) | 97.1 (36.2) | 84.2 (29.0) | 67.9 (19.9) | 54.2 (12.3) | 104.4 (40.2) |
| Mean daily maximum °F (°C) | 32.6 (0.3) | 36.9 (2.7) | 49.7 (9.8) | 61.2 (16.2) | 70.9 (21.6) | 81.1 (27.3) | 91.3 (32.9) | 90.9 (32.7) | 79.4 (26.3) | 62.1 (16.7) | 46.4 (8.0) | 35.2 (1.8) | 61.5 (16.4) |
| Daily mean °F (°C) | 19.4 (−7.0) | 23.7 (−4.6) | 35.4 (1.9) | 46.1 (7.8) | 55.8 (13.2) | 65.6 (18.7) | 73.5 (23.1) | 72.0 (22.2) | 61.0 (16.1) | 46.2 (7.9) | 32.3 (0.2) | 21.9 (−5.6) | 46.1 (7.8) |
| Mean daily minimum °F (°C) | 6.3 (−14.3) | 10.6 (−11.9) | 21.0 (−6.1) | 31.0 (−0.6) | 40.8 (4.9) | 50.1 (10.1) | 55.6 (13.1) | 53.0 (11.7) | 42.6 (5.9) | 30.4 (−0.9) | 18.3 (−7.6) | 8.6 (−13.0) | 30.7 (−0.7) |
| Mean minimum °F (°C) | −23.5 (−30.8) | −15.4 (−26.3) | −4.1 (−20.1) | 13.1 (−10.5) | 24.3 (−4.3) | 36.1 (2.3) | 43.2 (6.2) | 37.6 (3.1) | 25.5 (−3.6) | 12.3 (−10.9) | −6.3 (−21.3) | −17.2 (−27.3) | −32.0 (−35.6) |
| Record low °F (°C) | −45 (−43) | −45 (−43) | −40 (−40) | −5 (−21) | 13 (−11) | 21 (−6) | 33 (1) | 31 (−1) | 16 (−9) | −11 (−24) | −29 (−34) | −49 (−45) | −49 (−45) |
| Average precipitation inches (mm) | 0.44 (11) | 0.48 (12) | 0.70 (18) | 1.65 (42) | 2.92 (74) | 2.31 (59) | 1.78 (45) | 1.02 (26) | 1.26 (32) | 1.04 (26) | 0.50 (13) | 0.41 (10) | 14.51 (368) |
| Average snowfall inches (cm) | 5.6 (14) | 5.0 (13) | 5.4 (14) | 2.2 (5.6) | 0.8 (2.0) | 0.0 (0.0) | 0.0 (0.0) | 0.0 (0.0) | 0.1 (0.25) | 1.6 (4.1) | 3.7 (9.4) | 5.5 (14) | 29.9 (76.35) |
| Average precipitation days (≥ 0.01 in) | 6.2 | 6.3 | 6.3 | 8.4 | 10.5 | 10.4 | 8.0 | 5.8 | 6.3 | 7.2 | 5.7 | 5.9 | 87.0 |
| Average snowy days (≥ 0.1 in) | 4.7 | 4.4 | 3.2 | 1.3 | 0.3 | 0.0 | 0.0 | 0.0 | 0.0 | 1.0 | 3.2 | 4.8 | 22.9 |
| Source 1: NOAA ||||||||||||||
| Source 2: National Weather Service ||||||||||||||

### Major highways

* Interstate 94
* U.S. Highway 12
* U.S. Highway 212
* Montana Highway 59

### Transit

* Jefferson Lines

### Adjacent counties

* Prairie County - north
* Fallon County - east
* Carter County - southeast
* Powder River County - south
* Rosebud County - west
* Garfield County - northwest

## Demographics
### 2020 census

As of the 2020 census, there were 11,867 people living in the county.

### 2010 census

As of the 2010 census, there were 11,699 people, 5,031 households, and 3,014 families living in the county. The population density was 3.1 inhabitants per square mile (1.2/km$^2$). There were 5,560 housing units at an average density of 1.5 per square mile (0.58/km$^2$). The racial makeup of the county was 95.5% white, 1.7% American Indian, 0.3% black or African American, 0.3% Asian, 0.1% Pacific islander, 0.5% from other races, and 1.6% from two or more races. Those of Hispanic or Latino origin made up 2.2% of the population. In terms of ancestry, 33.6% were German, 18.3% were Irish, 14.3% were American, 14.1% were Norwegian, and 10.6% were English.
Of the 5,031 households, 27.3% had children under the age of 18 living with them, 46.6% were married couples living together, 9.0% had a female householder with no husband present, 40.1% were non-families, and 34.3% of all households were made up of individuals. The average household size was 2.24 and the average family size was 2.88. The median age was 42.1 years.
The median income for a household in the county was $38,913 and the median income for a family was $49,011. Males had a median income of $37,535 versus $26,576 for females. The per capita income for the county was $21,676. About 12.4% of families and 15.7% of the population were below the poverty line, including 19.8% of those under age 18 and 14.6% of those age 65 or over.

## Politics

Custer County is a staunchly Republican county, like many others in eastern Montana, increasingly so in recent elections. The last Democrat to carry the county was Lyndon Johnson in 1964.
United States presidential election results for Custer County, Montana :
| Year | Republican | Republican | Democratic | Democratic | Third party(ies) | Third party(ies) |
| Year | No. | % | No. | % | No. | % |
| 2024 | 4,208 | 72.54% | 1,385 | 23.88% | 208 | 3.59% |
| 2020 | 4,205 | 71.76% | 1,514 | 25.84% | 141 | 2.41% |
| 2016 | 3,657 | 70.53% | 1,176 | 22.68% | 352 | 6.79% |
| 2012 | 3,373 | 62.87% | 1,833 | 34.17% | 159 | 2.96% |
| 2008 | 3,047 | 55.89% | 2,267 | 41.58% | 138 | 2.53% |
| 2004 | 3,297 | 65.31% | 1,630 | 32.29% | 121 | 2.40% |
| 2000 | 3,156 | 64.34% | 1,501 | 30.60% | 248 | 5.06% |
| 1996 | 2,467 | 46.29% | 2,115 | 39.69% | 747 | 14.02% |
| 1992 | 2,105 | 37.52% | 1,968 | 35.07% | 1,538 | 27.41% |
| 1988 | 3,007 | 55.05% | 2,343 | 42.90% | 112 | 2.05% |
| 1984 | 3,879 | 65.53% | 1,982 | 33.49% | 58 | 0.98% |
| 1980 | 3,533 | 60.75% | 1,822 | 31.33% | 461 | 7.93% |
| 1976 | 3,120 | 55.25% | 2,425 | 42.94% | 102 | 1.81% |
| 1972 | 3,486 | 63.31% | 1,875 | 34.05% | 145 | 2.63% |
| 1968 | 2,831 | 58.06% | 1,760 | 36.10% | 285 | 5.84% |
| 1964 | 2,302 | 45.13% | 2,790 | 54.70% | 9 | 0.18% |
| 1960 | 2,943 | 55.00% | 2,393 | 44.72% | 15 | 0.28% |
| 1956 | 3,240 | 58.30% | 2,317 | 41.70% | 0 | 0.00% |
| 1952 | 3,461 | 62.53% | 2,050 | 37.04% | 24 | 0.43% |
| 1948 | 1,845 | 43.28% | 2,359 | 55.34% | 59 | 1.38% |
| 1944 | 1,830 | 46.96% | 2,038 | 52.30% | 29 | 0.74% |
| 1940 | 2,017 | 41.73% | 2,782 | 57.55% | 35 | 0.72% |
| 1936 | 1,381 | 29.30% | 3,196 | 67.81% | 136 | 2.89% |
| 1932 | 1,675 | 36.99% | 2,729 | 60.27% | 124 | 2.74% |
| 1928 | 2,503 | 64.08% | 1,386 | 35.48% | 17 | 0.44% |
| 1924 | 1,654 | 43.78% | 412 | 10.91% | 1,712 | 45.31% |
| 1920 | 2,347 | 64.53% | 1,127 | 30.99% | 163 | 4.48% |
| 1916 | 1,615 | 37.05% | 2,602 | 59.69% | 142 | 3.26% |
| 1912 | 695 | 21.70% | 1,068 | 33.34% | 1,440 | 44.96% |
| 1908 | 967 | 60.66% | 531 | 33.31% | 96 | 6.02% |
| 1904 | 824 | 72.22% | 285 | 24.98% | 32 | 2.80% |
| 1900 | 980 | 66.94% | 477 | 32.58% | 7 | 0.48% |
| 1896 | 723 | 51.50% | 676 | 48.15% | 5 | 0.36% |
| 1892 | 680 | 52.67% | 537 | 41.60% | 74 | 5.73% |

## Economy

Agriculture (dryland farming) and cattle raising provide the bulk of Custer County economy. Miles City serves as the center of commerce in an area extending for 100 miles in every direction. As of 2009 the county's largest employers were Holy Rosary Healthcare, Sanjel USA, Stockman Bank, and Walmart.

## Communities
### City

* Miles City (county seat)

### Town

* Ismay

### Unincorporated communities

* Bonfield, Montana
* Kinsey
* Knowlton, Montana
* Mizpah, Montana
* Tusler, Montana
* Volborg