Colorado’s over-65 population has never been higher and is projected to make up 20% of the overall state population by 2035. Here are Colorado’s top five oldest counties by median age, based on the latest state demographic data (from 2022), followed by the top five youngest counties. Colorado’s statewide median age was 37.7, slightly below the national median of 38.9.

Oldest

Custer (59.3)
Hinsdale (55.6)
Huerfano (55.6)
Mineral (55.1)
Ouray (54.8)

Youngest

Denver (34.6)
Weld (34.9)
Adams (35.0)
Alamosa (35.0)
El Paso (35.3)