 According to the U.S. Census Bureau, the county has a total area of , of which is land and (3.0%) is water.Pulaski County is the site of Claytor Lake State Park, which is located on Claytor Lake, a , long man-made lake on the New River created for a hydroelectric project of Appalachian Power Company.It is named for W. Graham Claytor, Sr. (1886–1971) of Roanoke, Virginia, a vice president of Appalachian Power who supervised construction of the dam and creation of the lake.