Adams County, Colorado

Adams County
Adams County Government Center in Brighton
Location within the U.S. state of Colorado
Colorado's location within the U.S.
Coordinates: 39°52′N 104°21′W / 39.87°N 104.35°W / 39.87; -104.35
Country United States
State Colorado
FoundedApril 15, 1901
Named afterAlva Adams
SeatBrighton
Largest cityThornton
Area
  Total
1,184 sq mi (3,070 km2)
  Land1,168 sq mi (3,030 km2)
  Water16 sq mi (40 km2)  1.4%
Population
 (2020)
  Total
519,572
  Estimate 
(2024)
542,973
  Density440/sq mi (170/km2)
Time zoneUTC−7 (Mountain)
  Summer (DST)UTC−6 (MDT)
Congressional districts4th, 6th, 7th, 8th
Websitewww.adcogov.org

Adams County is a county located in the U.S. state of Colorado. As of the 2020 United States census, the population was 519,572. The county seat is Brighton, and the largest city is Thornton. The county is named for Alva Adams, an early Governor of the State of Colorado in 1887–1889. Adams County is part of the Denver metropolitan area.