Black Hawk is located adjacent to Central City, another historic mining settlement in Gregory Gulch. The two cities form the federally designated Central City/Black Hawk National Historic District. The area flourished during the mining boom of the late 19th century following the construction of mills and a railroad link to Golden. The town declined during the 20th century, but has been revived in recent years after the 1991 establishment of casino gambling following a statewide initiative in 1990. In early 2010, the Black Hawk city council passed a law banning the riding of bicycles in the town, drawing a reaction from bicycle advocacy groups and international press.