I recently downloaded a shapefile that shows the individual city and towns within a specific county. I noticed that part of the unincorporated portion of this county has polygons but there are parts of the unincorporated area that does not have a polygon. Does anyone know of a tool within ArcGIS Pro that could add a polygon for the unincorporated areas to the shapefile? I've attached an example of Rogers County, OK which has all the municipal boundaries. Part of the unincorporated area has a polygon but there is a large area that doesn't.