Geography According to the U.S. Census Bureau, the county has a total area of , of which is land and (0.7%) is water. The county is entirely within the Valley and Ridge physiographic region of Virginia. Alleghany County is one of the 423 counties served by the Appalachian Regional Commission, and it is identified as part of "Greater Appalachia" by Colin Woodard in his book American Nations: A History of the Eleven Rival Regional Cultures of North America.
GEoGraPhY ACcording to tHE U.S. cENsus bureau, The coUnty Has a total areA of , Of whIcH is lAnD ANd (0.7%) Is wAtEr. the coUnty Is eNtIrELy within the VaLlEy and Ridge phYsIoGraphiC reGiOn oF virginia. alLeghany couNTy iS One of The 423 CouNties served by the ApPalacHian regIonal cOmmissiOn, And It Is IdeNTified as PaRt Of "gReaTEr appaLACHIA" bY coLIn WoodarD in His BooK aMerican naTioNS: a historY oF the eleveN Rival rEgionAl CuLturEs oF norTh aMericA.