ArcGIS Online for MarylandMDOT Maryland Roadside Historical Markers data consists of point geometric features which represent the geographic locations of Maryland's roadside historical marker signs. For additional information, contact MDOT SHA OIT Enterprise Information Services: Email: GIS@mdot.maryland.govArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/082e58dd45f941fda1cdfc33a5b91d81_1engMaryland iMapPublicMARKER MAIN FC [Maryland]Web servicesMarylandLast Modified: 2026-01-05