The City and County of Broomfield (one of few consolidated city-counties) lies north of Denver. The municpality
of Broomfield was incorporated in 1961 in the southeastern corner of Boulder County. The city grew through several annexations over the
following decades, its growth taking it into the adjoining counties of Adams, Jefferson, and Weld. By the 1990s, city leaders were pushing
for the creation of a county entity to coincide with the city and eliminate the inefficiencies inherent in dealing with four different
counties. Such a move required an amendment to the Colorado State Constitution, and such an amendment was passed in 1998.
On November 15, 2001, Broomfield County became the 64th county in the state of Colorado.
Source: wikipedia.org