Longmont, city, Boulder County, northern Colorado, in the fertile St. Vrain Valley; incorporated as a city 1961. It is a processing center for an area in which turkeys and vegetables are produced. Manufactures include computer equipment and automobile accessories. The county fairground is here. The city was laid out in 1871 and grew as the center of a farming area, especially after the arrival of a railroad in 1873. It is named for nearby Longs Peak, which was sighted in 1820 by the explorer Major Stephen H. Long. Population 42,942 (1980); 51,555 (1990); 71,093 (2000).
