Boulder, Colorado

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.