The status of each historical resource on the web map is indicated by different colored dots on the map. 

The Berks County Planning Commission distributed survey forms and paper maps of historical site locations to historical societies, the Berks County Conservancy, and historical representatives from various municipalities.  The survey forms requested detailed information for each historic site such as the type of architectural structure, year built, type of structural materials, historical function, and current function.  The survey forms were completed with as much information as possible and returned to the Berks County Planning Commission for further processing.

In addition to the survey forms, the Pennsylvania Historic Museum Commission (PHMC) provided information on historical structures in Berks County.  This data is also being compiled and updated to the Berks County Planning Commission's historical resources inventory.

The Berks County Historic Preservation Trust is also working with the Berks County Planning Commission to update information and complete more survey forms.