Area code 859

Area code 859 serves the city of Lexington and the central portion of the Commonwealth of Kentucky. It was created in a split from area code 606 in 1999.

Its service area encompasses the following Kentucky counties (the boundary closely, but not exactly, tracks county lines):

By far the largest city in the 859 territory is Lexington. The next largest area is the Kentucky portion of the Cincinnati metropolitan area. It includes smaller cities and towns such as Nicholasville, Richmond, Danville, Covington, Versailles, Florence, Mount Sterling and Winchester.

The numbers 859 spell out "UKY" on a standard keypad—a nod to Lexington being home of the University of Kentucky.

Conventional wisdom would have suggested that Lexington and Northern Kentucky would have retained 606 in the 1999 split. Lexington was by far the largest city in the old 606 territory, and it and Northern Kentucky accounted for two-thirds of the old 606's population. However, several counties in eastern Kentucky are among the poorest in the nation. The Kentucky Public Service Commission and BellSouth (now part of AT&T), then the region's main telephone carrier, decided to let the rural portion retain 606 in order to spare a notoriously impoverished area the added expense and burden of switching to a new area code.

...
Wikipedia