Boulder County, Colorado

Boulder County
Boulder County
County
	Boulder County Courthouse
	Seal
	Location within the U.S. state of Colorado
	Colorado's location within the U.S.
	Coordinates: 40°05′N 105°22′W / 40.09°N 105.36°W
Country	United States
State	Colorado
Founded	November 1, 1861
Named for	large granite boulders in area
Seat	Boulder
Largest city	Boulder
Area
• Total	740 sq mi (1,900 km2)
• Land	726 sq mi (1,880 km2)
• Water	14 sq mi (40 km2) 1.9%
Population (2020)
• Total	330,758
• Density	460/sq mi (176/km2)
Time zone	UTC−7 (Mountain)
• Summer (DST)	UTC−6 (MDT)
Congressional districts	2nd, 4th
Website	www.bouldercounty.org

Boulder County is a county located in the U.S. state of Colorado of the United States. As of the 2020 census, the population was 330,758.^[1] The most populous municipality in the county and the county seat is Boulder.^[2]

Boulder County comprises the Boulder, Colorado Metropolitan Statistical Area, which is included in the Denver–Aurora, Colorado Combined Statistical Area.^[3]

^ ^a ^b "U.S. Census Bureau QuickFacts". U.S. Census Bureau. Retrieved September 4, 2021.
^ "Find a County". National Association of Counties. Archived from the original on May 31, 2011. Retrieved June 7, 2011.
^ "OMB Bulletin No. 10-02: Update of Statistical Area Definitions and Guidance on Their Uses" (PDF). Office of Management and Budget. December 1, 2009. Archived (PDF) from the original on January 21, 2017. Retrieved April 19, 2012 – via National Archives.