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.
Read more on Wikipedia