The county was founded in 1810 and was named for the Rockcastle River which runs through it. The river, in turn, is named for its majestic rock cliffs. Rockcastle county is surrounded by Madison, Jackson, Garrard, Lincoln, Pulaski and, Laurel counties and the coutny seat is Mt. Vernon. With the county having a total area of 318 square miles, it has a population count of 17,056.