Colorado's labor force, the number of people working or looking for work, has undergone significant changes over the last several decades. Driven, in large part, by the changing age distribution of Colorado, growth rates of the labor force are expected to slow significantly over the forecast horizon of 2040 as compared to historical growth. We are currently nearing the middle of a decade during which Colorado's older population will rapidly become a larger share of its total population. In the long run, the trend of growth in the labor force for Colorado will reflect the aging of the post-World War II baby boomers as well as the migrants that have and will continue to relocate to Colorado for jobs. The labor force in 2040 will look considerably different from today's labor force. The labor force in 2040 will be much larger in number, it will be older, and it will include a larger share of females. Additionally, the labor force will be smaller relative to the total population it supports. Impacts include increased competition for the pool of skilled workers available, the potential slowing of housing development, and downward pressure on income. This report describes the changing age distribution of Colorado, its impacts on the labor force, as well as the potential impacts of the changes in the labor force. The data for this report are based on the 2008-2010 American Community Survey, the 2010 Current Population Survey, and the 2012 National BLS forecasts for labor force participation by age group.