Broomfield County: History
The Broomfield post office opened on September 26, 1884. Historians speculate that the town was named for the sorghum grown in the area, also known as broomcorn, which had stalks that were sold to make brooms and whisk brooms.
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 is now 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 Denver–Boulder Turnpike was constructed through the Broomfield area to speed automobile travel between the state capital of Denver and the university city of Boulder. Construction of the toll road began in 1950 and the turnpike was opened to traffic on January 19, 1952, with the sole toll plaza at Broomfield with access to U.S. Route 287 through the town. The toll to travel from Federal Boulevard in Adams County to Broomfield was 10 cents and the toll from Broomfield to Boulder was 15 cents, or 25 cents for the whole route.
The City of Broomfield was incorporated on June 6, 1961, in the southeastern corner of Boulder County. The Denver–Boulder Turnpike was a common commuting route and Broomfield became a popular residential area. On September 14, 1967, having paid off its construction and operating expenses, the turnpike was made free and became the official route of U.S. Route 36 between Denver, Boulder, and the Rocky Mountain National Park. The turnpike became the first public toll road in the United States to become free.
In the 1990s, after three decades of aggressive annexation, the City of Broomfield had expanded into Adams, Jefferson, and Weld counties in addition to Boulder. City leaders felt increasing chagrin with the need to deal with four different county governments, four separate county sales tax bases, and four separate court districts. They began pushing to make Broomfield a consolidated city-county similar to Denver, reasoning that they could provide services more responsively if Broomfield had its own county government.
The city sought an amendment to the state constitution to create a new county. The amendment was passed in 1998, after which a three-year transition period followed.
On November 15, 2001, Broomfield County became the 64th and least extensive county of Colorado. It is the newest county in Colorado (and in the entire United States, if county equivalents are not included).