Boulder, city, seat of Boulder County, northern Colorado, in a fertile farm valley at the foot of the Flatiron Range of the Rocky Mountains; incorporated as a city 1918. Boulder is an educational and research center, site of the University of Colorado (1876) and the National Center for Atmospheric Research. The National Institute of Standards and Technology has a major laboratory here. The city owns Arapahoe Glacier, from which it obtains much of its water supply. Boulder was settled in 1858 as a mining community; it was reached by railroad in 1873. Population 76,685 (1980); 83,312 (1990); 90,543 (1998 estimate).
