St. Anthony: Demographics & People

3,911 people call St. Anthony home, in 1,258 households. Population grew 2.4% from 3,818 (2022) to 3,911 (2024). Median age 32.4 years. (7.6y younger than Fremont County; 5.2y younger than Idaho). Children under 18 are 23% of the population. Population is 67% White (non-Hispanic) and 22% Hispanic or Latino. The community is somewhat diverse (Simpson index 0.33). 73% of households are family-led. County is losing 303 residents per year (2022-2023). County health: 34% adult obesity, 14% smoke.

Population & Trend

Population grew 2.4% from 3,818 (2022) to 3,911 (2024) — about 4.1× the recent U.S. annual rate of ~0.6%/yr. Estimated 2026 population: ~4,007 (extrapolated at 1.2%/yr trend). Census Bureau Vintage estimate: 4,137.

Census data vintage2024
Population13,388 people
Annual growth rate · Population change2.4%
Annual growth rate · Population (2022)3,818
Annual growth rate · Population (2024)3,911
Annual growth rate · Population growingYes
Annual growth rate · Trend categorygrowing
Population3,911 people
Population Estimate4,137

Sources: Census ACS 5-Year 2023, Table B01003  ·  Refreshed 2026-04-12

Age Distribution

Median age 32.4y is 6.5 years younger than the U.S. median (38.9y). Children under 18 make up 23% — above the U.S. share of ~22%.

Age Summary · Median age32.4 years (vs Idaho 37.6y)
Age Summary · Children Pct23.4%
Age Summary · Characteryoung professional
Population under 18916
Median age32.4 years (vs Idaho 37.6y)

Sources: Census ACS 5-Year 2023  ·  Refreshed 2026-04-12

Race, Ethnicity & Diversity

Of 3,911 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.33 (0 = single group, 1 = perfectly even distribution); this is read as somewhat diverse.

White residents2,971
Black residents9
Asian residents7
Hispanic or Latino residents762
Diversity Index · Diversity index (Simpson)33.1%
Diversity Index · Diversity labelsomewhat diverse
Diversity Index · Groups counted4
Diversity Index · Largest group share79.2%
Asian population0.4%
Black population0.4%
Hispanic or Latino population22.0%
White (non-Hispanic) population66.6%

Sources: Census ACS 5-Year 2023  ·  Refreshed 2026-04-12

Ancestry

Self-reported ancestry from Census ACS — what residents report as their ethnic origin, separate from race. Counts can exceed population because people can list multiple ancestries.

Top (8)

(unnamed)
English
(unnamed)
Hispanic Total
(unnamed)
Puerto Rican
(unnamed)
German
(unnamed)
Irish
(unnamed)
American
(unnamed)
Polish
(unnamed)
Italian

Citizenship & Origin

Where residents were born and their citizenship status (Census ACS). 0.4% are foreign-born — below the U.S. average of 13.9%. 6% have naturalized to U.S. citizenship.

Residents born in this state2,115
Residents born in another state1,546
Share born in this state54.1%
Share born in another state45.9%
Native-born U.S. citizens39.5%
Foreign-born residents0.4%
Naturalized citizens6.0%
Total foreign-born residents144
From Africa7

Households & Family Composition

1,258 households. Averaging 2.9 people each — larger than the U.S. average of 2.5. 73% are family households — above the U.S. share of ~65%. Of 842 families, 27% are married couples with children.

Children under 18908
Total families842
Married couples with children227
Single-parent households52
Average household size2.90
Women who gave birth (past year)13.9%
Grandparents living with grandchildren183
Grandparents responsible for grandchildren20
Family households922 households
Households that are families73.3%
Total households1,258 households

Sources: Census ACS 5-Year 2023  ·  Refreshed 2026-04-12

Residential Stability & Migration

How long residents have lived here and where they came from. 13.6% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is losing 303 residents per year on net (IRS migration data).

Moved within the county (past year)13.6%
Migration · People moving in (annual)14,093
Migration · People moving out (annual)14,396
Migration · Net migration (in − out)-303
Migration · Year2022-2023

Sources: IRS SOI Migration 2021-2022  ·  Refreshed 2026-04-12

Disability

Census ACS measures self-reported functional limitations — vision, hearing, mobility, cognitive, self-care, or independent-living. The U.S. baseline disability rate is about 12–13%; rates trend higher with median age.

Residents with a disability397
Disability rate11.6%

Group Quarters

Group quarters are non-household living arrangements counted by the Census — college dormitories, nursing homes, military barracks, group homes, correctional facilities, and similar institutional or shared housing. 343 residents live in group quarters (8.8% of population).

Living in group quarters343

Other

Congressional District · District2
Congressional District · FormattedID-02
Congressional District · Congress118th
Cdc Birth Rate · Fips16,043
Cdc Birth Rate · State Fips16
Cdc Birth Rate · County Fips43
Cdc Birth Rate · CountyFremont
Cdc Birth Rate · Birth Rate18.3%
Cdc Birth Rate · Lower Ci13.50
Cdc Birth Rate · Upper Ci24.10
Cdc Mortality · Fips16,043
Cdc Mortality · CountyFremont County
Cdc Mortality · Urban RuralMicropolitan
Cdc Mortality · Total Deaths 2020 2023351
Cdc Vaccination · Fips16,043
Cdc Vaccination · CountyFremont County
Cdc Vaccination · Dose1 Pop Pct54.0%
Cdc Vaccination · Series Complete Pct47.2%
Cdc Vaccination · Booster Pct40.6%
Cdc Vaccination · Population 201913,099
Cdc Vaccination · Metro StatusNon-metro
Family Score · Score2.50
Family Score · Schools3
Family Score · Children Pct23.4%
Family Score · Ratinglimited
Town Summary · Key Factspopulation 3,911, growing, young professional, middle-class, mixed
Town Summary · Population3,911 people
Town Summary · CountyFremont County

Sources: Census place-to-CD118 crosswalk (place_fips) · federal dataset cascade