St. Marks: Demographics & People
156 people call St. Marks home, in 33 households. Population grew 79.3% from 87 (2022) to 156 (2024). Median age 21.4 years. (14.6y younger than Sedgwick County; 16.1y younger than Kansas). Children under 18 are 46% of the population. Population is 88% White (non-Hispanic) and 12% Hispanic or Latino. The community is somewhat diverse (Simpson index 0.24). 100% of households are family-led. County is gaining 856 residents per year (2022-2023). County health: 34% adult obesity, 17% smoke.
- 4.7 people per household.
- 0% non-family households (singles, roommates).
Population & Trend
Population grew 79.3% from 87 (2022) to 156 (2024) — about 132.2× the recent U.S. annual rate of ~0.6%/yr. Estimated 2026 population: ~304 (extrapolated at 39.7%/yr trend). Census Bureau Vintage estimate: 609.
| Census data vintage | 2024 |
|---|---|
| Population | 523,824 people |
| Annual growth rate · Population change | 79.3% |
| Annual growth rate · Population (2022) | 87 |
| Annual growth rate · Population (2024) | 156 |
| Annual growth rate · Population growing | Yes |
| Annual growth rate · Trend category | booming |
| Population | 156 people |
| Population Estimate | 609 |
Sources: Census ACS 5-Year 2023, Table B01003 · Refreshed 2026-04-12
Age Distribution
Median age 21.4y is 17.5 years younger than the U.S. median (38.9y). Children under 18 make up 46% — above the U.S. share of ~22%.
| Age Summary · Median age | 21.4 years (vs Kansas 37.5y) |
|---|---|
| Age Summary · Children Pct | 46.2% |
| Age Summary · Character | young community |
| Population under 18 | 72 |
| Median age | 21.4 years (vs Kansas 37.5y) |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Race, Ethnicity & Diversity
Of 156 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.24 (0 = single group, 1 = perfectly even distribution); this is read as somewhat diverse.
| White residents | 87 |
|---|---|
| Hispanic or Latino residents | 14 |
| Diversity Index · Diversity index (Simpson) | 23.9% |
| Diversity Index · Diversity label | somewhat diverse |
| Diversity Index · Groups counted | 2 |
| Diversity Index · Largest group share | 86.1% |
| Hispanic or Latino population | 11.5% |
| White (non-Hispanic) population | 88.5% |
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 (3)
Citizenship & Origin
Where residents were born and their citizenship status (Census ACS).
| Residents born in this state | 156 |
|---|---|
| Share born in this state | 100.0% |
| Total foreign-born residents | 44,421 |
Households & Family Composition
33 households. Averaging 4.1 people each — larger than the U.S. average of 2.5. 100% are family households — above the U.S. share of ~65%. Of 21 families, 67% are married couples with children.
| Children under 18 | 45 |
|---|---|
| Total families | 21 |
| Married couples with children | 14 |
| Average household size | 4.14 |
| Grandparents living with grandchildren | 8,595 |
| Grandparents responsible for grandchildren | 3,210 |
| Family households | 33 households |
| Households that are families | 100.0% |
| Total households | 33 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. The surrounding county is gaining 856 residents per year on net (IRS migration data).
| Migration · People moving in (annual) | 473,375 |
|---|---|
| Migration · People moving out (annual) | 472,519 |
| Migration · Net migration (in − out) | 856 |
| 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 | 15 |
|---|---|
| Disability rate | 14.0% |
Other
| Congressional District · District | 4 |
|---|---|
| Congressional District · Formatted | KS-04 |
| Congressional District · Congress | 118th |
| Cdc Birth Rate · Fips | 20,173 |
| Cdc Birth Rate · State Fips | 20 |
| Cdc Birth Rate · County Fips | 173 |
| Cdc Birth Rate · County | Sedgwick |
| Cdc Birth Rate · Birth Rate | 24.6% |
| Cdc Birth Rate · Lower Ci | 23.30 |
| Cdc Birth Rate · Upper Ci | 25.90 |
| Cdc Mortality · Fips | 20,173 |
| Cdc Mortality · County | Sedgwick County |
| Cdc Mortality · Urban Rural | Medium metro |
| Cdc Mortality · Total Deaths 2020 2023 | 22,384 |
| Cdc Vaccination · Fips | 20,173 |
| Cdc Vaccination · County | Sedgwick County |
| Cdc Vaccination · Dose1 Pop Pct | 67.7% |
| Cdc Vaccination · Series Complete Pct | 58.1% |
| Cdc Vaccination · Booster Pct | 47.4% |
| Cdc Vaccination · Population 2019 | 516,042 |
| Cdc Vaccination · Metro Status | Metro |
| Family Score · Score | 10 |
| Family Score · Schools | 20 |
| Family Score · Children Pct | 46.2% |
| Family Score · Rating | excellent |
| Town Summary · Key Facts | population 156, booming, young community, high crime, heritage: German/English |
| Town Summary · Population | 156 people |
| Town Summary · County | Sedgwick County |
Sources: Census place-to-CD118 crosswalk (place_fips) · federal dataset cascade