According to Bureau of Labor Statistics (BLS) provisional estimates, in July 2003 the seasonally adjusted civilian labor force in Colorado numbered 2,477,800, with approximately 141,700 workers unemployed, yielding an unemployment rate of 5.7%, compared to the national average of 6.2% for the same period. Since the beginning of the BLS data series in 1978, the highest unemployment rate recorded was 8.8% in October 1982. The historical low was 2.6% in January 2001. In 2001, an estimated 7.0% of the labor force was employed in construction; 10.2% in manufacturing; 7.0% in transportation, communications, and public utilities; 19.6% in trade; 6.3% in finance, insurance, and real estate; 26.9% in services; 12.7% in government; and 2.0% in agriculture.
Colorado's labor history has been marked by major disturbances in the mining industry. From 1881 to 1886, the Knights of Labor led at least 35 strikes in the mines; during the 1890s, the Western Federation of Miners struck hard-rock mines in Telluride and Cripple Creek. The United Mine Workers, who came into the state in 1899, shut down operations at numerous mines in 1900 and 1903. Violence was common in these disputes. In one well-known episode, after striking miners and their families set up a tent colony at Ludlow, near Trinidad, the governor called out the militia; in the ensuing conflict, on 20 April 1914, the miners' tents were burned, killing two women and 11 children, an event that touched off a rebellion in the whole area. Federal troops restored order in June, and the strike ended with promises of improved labor conditions. In 1917, the state legislature created the Colorado Industrial Commission, whose purpose is to investigate all labor disputes.
The US Department of Labor reported that in 2002, 157,000 of Colorado's 1,999,000 employed wage and salary workers were members of unions. This represented 7.8% of those so employed, down from 8.7% in 2001. The national average is 13.2%. In all, 180,000 workers (9.0%) were represented by unions. In addition to union members, this category includes workers who report no union affiliation but whose jobs are covered by a union contract.