20250917 12123800 1.0 TRUE County Boundary (SHA) The Maryland county boundaries were built using the USGS Topo Quads, county boundaries from the county governments, monument points, and historic records from the Maryland Archive. County boundaries are a key geographic asset in our mapping process and roadway data collection. (Data as downloaded from SHA on 6/3/16 has 2014 in file name: "SHA_POLY_POLBOUNDSW_MD_2014") SHA