The date when the original maps were first printed varies considerably but ranges from about 1976 to 1989. IMPORTANT NOTE: Potential purchasers are encouraged to research details on the maps thoroughly before buying as the age of the maps may mean that they are not suitable for your intended purpose. Any man-made feature created after 1989 is not shown on the maps. For example a significant number of roads within the Perth Metro area are not shown as considerable development has occurred since the maps were produced. The maps are primarily aimed as use with OziExplorer as basemaps for recreational activities in existing bush areas that (more typically) have seen little change over the years. The maps show all significant natural features (lakes, swamps, rivers, creeks, hills, coastal features etc) along with cultural features (tracks, roads, highways, towns, dams, nature reserves etc) present at the time the data was collected for use to draft the maps. Some of the maps have contours at 10metre intervals while others have more detail with contours at 5 metre intervals. The maps on the DVD have been specifically created for use with the popular OziExplorer GPS Mapping Software. Calibration files are included so users can start using the maps immediately. Elevation data (~90m spot heights) is also included for use with OziExplorer3D, a program that produces 3D terrain models utilising the maps and the elevation data. For those without OziExplorer or OziExplorer3D it is recommended that users get the free trial version of these programs available for download from www.oziexplorer.com.