St. Maries: Demographics & People
Census counts 2,915 people in St. Maries, in 1,153 households. Population shrank 3.9% from 3,032 (2022) to 2,915 (2024). Median age 41.1 years. (4.4y younger than Benewah County; 3.5y older than Idaho). Children under 18 are 23% of the population. Population is 93% White (non-Hispanic) and 3% Hispanic or Latino. The community is relatively homogeneous (Simpson index 0.04). 61% of households are family-led. County is gaining 387 residents per year (2022-2023). County health: 34% adult obesity, 17% smoke.
- 2.5 people per household.
- 39% non-family households (singles, roommates).
Population & Trend
Population shrank 3.9% from 3,032 (2022) to 2,915 (2024). Estimated 2026 population: ~2,803 (extrapolated at -1.9%/yr trend). Census Bureau Vintage estimate: 2,659.
| Census data vintage | 2024 |
|---|---|
| Population | 9,530 people |
| Annual growth rate · Population change | -3.9% |
| Annual growth rate · Population (2022) | 3,032 |
| Annual growth rate · Population (2024) | 2,915 |
| Annual growth rate · Trend category | declining |
| Population | 2,915 people |
| Population Estimate | 2,659 |
Sources: Census ACS 5-Year 2023, Table B01003 · Refreshed 2026-04-12
Age Distribution
Median age 41.1y is 2.2 years older than the U.S. median (38.9y). Children under 18 make up 23% — near the U.S. share of ~22%.
| Age Summary · Median age | 41.1 years (vs Idaho 37.6y) |
|---|---|
| Age Summary · Children Pct | 22.6% |
| Age Summary · Character | established |
| Population under 18 | 659 |
| Median age | 41.1 years (vs Idaho 37.6y) |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Race, Ethnicity & Diversity
Of 2,915 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.04 (0 = single group, 1 = perfectly even distribution); this is read as relatively homogeneous.
| White residents | 2,931 |
|---|---|
| Black residents | 4 |
| Hispanic or Latino residents | 57 |
| Diversity Index · Diversity index (Simpson) | 4.0% |
| Diversity Index · Diversity label | relatively homogeneous |
| Diversity Index · Groups counted | 3 |
| Diversity Index · Largest group share | 98.0% |
| Black population | 0.1% |
| Hispanic or Latino population | 2.7% |
| White (non-Hispanic) population | 93.2% |
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)
Citizenship & Origin
Where residents were born and their citizenship status (Census ACS). 0.7% are foreign-born — below the U.S. average of 13.9%.
| Residents born in this state | 1,400 |
|---|---|
| Residents born in another state | 1,496 |
| Share born in this state | 48.0% |
| Share born in another state | 52.0% |
| Native-born U.S. citizens | 51.3% |
| Foreign-born residents | 0.7% |
| Total foreign-born residents | 15 |
| From Europe | 7 |
Households & Family Composition
1,153 households. Averaging 2.5 people each — matches the U.S. average of 2.5. 61% are family households — below the U.S. share of ~65%. Of 732 families, 44% are married couples with children.
| Children under 18 | 685 |
|---|---|
| Total families | 732 |
| Married couples with children | 323 |
| Single-parent households | 34 |
| Average household size | 2.49 |
| Women who gave birth (past year) | 16.6% |
| Grandparents living with grandchildren | 42 |
| Grandparents responsible for grandchildren | 20 |
| Family households | 703 households |
| Households that are families | 61.0% |
| Total households | 1,153 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. 10.0% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is gaining 387 residents per year on net (IRS migration data).
| Moved within the county (past year) | 10.0% |
|---|---|
| Migration · People moving in (annual) | 9,693 |
| Migration · People moving out (annual) | 9,306 |
| Migration · Net migration (in − out) | 387 |
| Migration · Population growing | Yes |
| Migration · Year | 2022-2023 |
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 disability | 293 |
|---|---|
| Disability rate | 12.7% |
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. 79 residents live in group quarters (2.7% of population).
| Living in group quarters | 79 |
|---|
Other
| Congressional District · District | 1 |
|---|---|
| Congressional District · Formatted | ID-01 |
| Congressional District · Congress | 118th |
| Cdc Birth Rate · Fips | 16,009 |
| Cdc Birth Rate · State Fips | 16 |
| Cdc Birth Rate · County Fips | 9 |
| Cdc Birth Rate · County | Benewah |
| Cdc Birth Rate · Birth Rate | 32.1% |
| Cdc Birth Rate · Lower Ci | 23.60 |
| Cdc Birth Rate · Upper Ci | 42.50 |
| Cdc Mortality · Fips | 16,009 |
| Cdc Mortality · County | Benewah County |
| Cdc Mortality · Urban Rural | Noncore |
| Cdc Mortality · Total Deaths 2020 2023 | 334 |
| Cdc Vaccination · Fips | 16,009 |
| Cdc Vaccination · County | Benewah County |
| Cdc Vaccination · Dose1 Pop Pct | 66.0% |
| Cdc Vaccination · Series Complete Pct | 56.1% |
| Cdc Vaccination · Booster Pct | 50.7% |
| Cdc Vaccination · Population 2019 | 9,298 |
| Cdc Vaccination · Metro Status | Non-metro |
| Family Score · Score | 3.00 |
| Family Score · Schools | 4 |
| Family Score · Children Pct | 22.6% |
| Family Score · Rating | limited |
| Town Summary · Key Facts | population 2,915, declining, established, middle-class, mixed |
| Town Summary · Population | 2,915 people |
| Town Summary · County | Benewah County |
Sources: Census place-to-CD118 crosswalk (place_fips) · federal dataset cascade