Jefferson County, MT Population

Overview

12,057

Total Population

47.5

Median age

48.95%

Female population %

104.3:100

Gender ratio (M:F)

65-69 years

Largest age group

61.4

Total dependency ratio

White

Largest racial group

335

Hispanic population

Sources: U.S. Census Bureau, American Community Survey (ACS) 2021

TABLE OF CONTENTS

Age

Jefferson County's population is old compared to the rest of the country:

The median age in Jefferson County is 47.5, compared to 38.8 nationwide, according to the American Community Survey 2017 - 2021 5 Year estimates.
Jefferson County's population under 18 was 20.49%, compared to the 22.51% nationwide.
Jefferson County's elderly or the senior population (over 65 age) was 21.86% as compared to 16.04% nationwide.
Of the total population in Jefferson County, 16.17% were under the age of 15, 15.20% aged 15 to 29, 46.76% aged 30 to 64, 20.08% aged 65 to 84, and 1.78% were 85 years of age and older.

There are 253 less females than males in Jefferson County:

The female percentage in the USA is 50.50% while the male percentage is 49.50%, compared to 48.95% females and 51.05% males in Jefferson County, MT.
The Jefferson County, MT gender ratio is 104.3:100 i.e. 104.3 men to 100 women (1.043).
For male population, the largest age group is 65-69 years with a population of 648.
For the female population, the largest age group is 60-64 years with a population of 564.

Jefferson County's population has become increasingly diverse:

Racial distribution of Jefferson County population: 93.38% are White, 0.45% are Black or African American, 1.17% are American Indian and Alaska Native, 0.14% are Asian, 0.41% are some other race and 4.45% are multiracial.
Jefferson County's racial breakdown clearly shows that there is an absolute majority of White population in the county.
By ethnicity, 335 is Hispanic or Latino (of any race), and 11,722 (97.22% of the total population) is Non-Hispanic.
The largest racial group in Jefferson County is White with a population of 11,259 (93.38% of the total population).

Jefferson County's population has not reached its peak yet and is showing a trend of further growth:

The peak population was 12,826 in the year 2022
From 2000 to 2010, Jefferson County's population increased by 1,374 (13.70%), as compared to the national growth of 9.63%.
From 2010 to 2020, Jefferson County's population increased by 734 (6.44%), according to Census Bureau's Population Estimates Program. For the same period, the rate of growth for the United States was 7.17%.
Between the year 2000 and 2022, Jefferson County's population was lowest in year 2000 at 10,032.