Northern Kentucky is the name often given to the northernmost (most typically the three northernmost) counties in Kentucky (Boone, Kenton, Campbell, shown in red on the map). Gallatin, Grant, Pendleton, and Bracken counties (highlighted in pink on the map) are often grouped with the aforementioned and are officially part of the Cincinnati Metropolitan Area, and are sometimes included in definitions of "Northern Kentucky." Historically, Trimble, Mason, and Lewis counties have also been included in "Northern Kentucky."