Boulder, Colorado

Boulder
Pearl Street Mall in downtown Boulder, 2009
Location of Boulder in Boulder County, Colorado
Boulder
Location within Colorado
Boulder
Location within the United States
Coordinates: 40°00′54″N 105°16′14″W / 40.0150°N 105.2705°W / 40.0150; -105.2705
CountryUnited States
StateColorado
CountyBoulder
Settled1858 as Boulder City, N.T.
IncorporatedNovember 4, 1871
Government
 • TypeHome rule city
 • MayorAaron Brockett (D)
 • Mayor Pro TemLauren Folkerts
Area
27.366 sq mi (70.877 km2)
 • Land26.328 sq mi (68.188 km2)
 • Water1.038 sq mi (2.689 km2)
Elevation
5,319 ft (1,621 m)
Population
 (2020)
108,250
 • Estimate 
(2024)
106,803
 • Rank12th in Colorado
324th in United States
 • Density4,112/sq mi (1,588/km2)
 • Metro
330,758 (155th)
 • CSA
3,623,560 (17th)
 • Front Range
5,055,344
DemonymBoulderite
GDP
 • Metro$35.608 billion (2022)
Time zoneUTC−07:00 (MST)
 • Summer (DST)UTC−06:00 (MDT)
ZIP Codes
80301-80310, 80314, 80321-80323, 80328, 80329
Area codes303/720/983
GNIS pop ID178680
GNIS city ID2409883
FIPS code08-07850
Major highways
WebsiteCity of Boulder

Boulder is a home rule city that is the county seat of, and the most populous municipality in, Boulder County, Colorado, United States. With a population of 108,250 at the 2020 census, it is the 12th-most populous city in Colorado. Boulder is the primary city of the Boulder, CO Metropolitan Statistical Area, which had 330,758 residents in 2020, and is part of the Front Range Urban Corridor.

Boulder is located at the base of the foothills of the Rocky Mountains, at an elevation of 5,430 feet (1,655 m) above sea level. The city is 25 miles (40 km) northwest of the Colorado state capital of Denver. Boulder is a college town, hosting the University of Colorado Boulder, the flagship and largest campus of the University of Colorado system, as well as numerous research institutes. Starting in 2027, Boulder will become the new home of the Sundance Film Festival.