St. Mary CDP, Montana Demographics & Population 2026

Population Overview

St. Mary CDP is a small community located in Montana. The total population is 209. It ranks as the 243rd most populous out of 470 cities and towns in Montana.

Age Demographics

The median age in St. Mary CDP is 22.0 years. This is 45% lower than the state median of 40.2 years. Only 7.2% of residents are under 18, indicating fewer families with children.

Economy, Income & Housing

The poverty rate stands at 52.6%. This is 336% higher than the state poverty rate of 12.0%. With more than one in five residents living below the poverty line, economic hardship is a significant challenge for the community. The unemployment rate is 8.9%. This is 136% higher than the state rate of 3.8%. 68.0% of occupied housing units are owner-occupied. This homeownership rate is 2% lower than the state average of 69.4%.

Race & Ethnicity

The largest racial or ethnic group in St. Mary CDP is White (non-Hispanic), making up 71.8% of the population. Hispanic or Latino residents account for 12.9%. The Hispanic or Latino population is significantly higher than the state average (12.9% vs 4.4%).

Education

34.3% of residents aged 25 and older hold a bachelor's degree or higher. This is about average than the state rate of 34.5%. Nationally, 35.0% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 100.0%.

Data Sources & Methodology

All demographic data for St. Mary CDP, Montana is sourced from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates (2019-2023). The ACS collects data from approximately 3.5 million households annually, providing reliable estimates for communities of all sizes. Comparisons are made against Montana state averages and national averages calculated from the same dataset. Rankings reflect the city's position among all 470 Census-designated places in Montana. For official data, visit data.census.gov.