Custer County, MT Population By Ancestry in 2021 (ACS-5Yrs)

Updated on March 3, 2025.

Based on the US Census ACS-5Yrs estimates, in 2021, among the 11.97K Custer County, MT population, 3.40K had German ancestry (28.39%), 3.11K had Unclassified ancestry (25.99%), and 1.60K had Irish ancestry (13.36%).

The chart below shows the top 10 ancestry groups by percentage, and the table below shows both the population and percentages for many ancestry groups.

You can see similar information for other Montana counties, and for Montana.

NB: People could belong to one or more ancestry groups.

Data Source: US Census Bureau.
Custer County, MT Percentage of Ancestry Population in 2021
German
Unclassified
Irish
Other Groups
English
Norwegian
French (except Basque)
American
Italian
Scottish
Custer County, MT Population By Ancestry in 2021
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Ancestry Population Percent of Pop. (%)
German 3398 28.39
Unclassified 3111 25.99
Irish 1599 13.36
Other Groups 1444 12.07
English 1226 10.24
Norwegian 1172 9.79
French (except Basque) 503 4.20
American 475 3.97
Italian 380 3.18
Scottish 314 2.62
Swedish 263 2.20
Polish 248 2.07
European 206 1.72
Scotch Irish 180 1.50
Welsh 174 1.45
Dutch 157 1.31
Danish 139 1.16
Russian 136 1.14
French Canadian 119 0.99
Czech 104 0.87
Ukrainian 78 0.65
Hungarian 76 0.64
Yugoslavian 68 0.57
Portuguese 67 0.56
British 49 0.41
Scandinavian 48 0.40
Finnish 42 0.35
Austrian 40 0.33
Swiss 39 0.33
Northern European 21 0.18
Armenian 20 0.17
Croatian 19 0.16
Belgian 17 0.14
Bulgarian 15 0.13
Slavic 15 0.13
Basque 13 0.11
Subsaharan African 11 0.09
African 11 0.09
Canadian 10 0.08
Greek 9 0.08
Assyrian/Chaldean/Syriac 7 0.06
Slovak 7 0.06
Iranian 2 0.02