Broomfield is a consolidated city and county in the U.S. state of Colorado. Broomfield has a consolidated city and county government which operates under Article XX, Sections 10-13 of the Constitution of the State of Colorado. The city is a part of the Denver-Aurora-Lakewood, CO Metropolitan Statistical Area. Its population was 55,889 at the 2010 United States Census., making it the 16th most populous municipality and the 13th most populous county in Colorado.
Several railroads figure in the development of this area. The Colorado Central Railroad built a narrow gauge line from Golden in 1873, the Denver, Utah and Pacific Railroad arrived in 1881, and the Denver, Marshall and Boulder Railway built a line through what would become Broomfield in 1886. The Denver, Utah and Pacific was widened to standard gauge in 1889. One of the early names for the area was Zang's Spur, after the railroad spur serving Adolph Zang's grain fields.
The municipality of Broomfield was incorporated in 1961 in the southeastern corner of Boulder County. While it is unsure how it received its name, most researchers guess it is from the broomcorn grown in the area, a tall sorghum that farmers sold for use as brooms and whisk brooms. Over the next three decades, the city grew through annexations, many of which crossed the county line into four adjacent counties: Adams, Boulder, Jefferson and Weld.