GeoMark is TerraGo's geospatial data extension to PDF markup. GeoMark allows notes and geometric objects (lines, polygons, etc.) to be added to a GeoPDF and allows these objects to be exported to GIS files.
Users of the pre-2017 maps can add and export Geomarkup using free Adobe Reader software and the Terrago Toolbar plugin. Exact behavior of the GeoMark tools varies between versions of Adobe Reader and the TerraGo Toolbar. GeoMark functions might not work on USGS topographic maps if you are using older versions of these software tools.
USGS topographic maps (US Topos) created after June 2017 are georeferenced but are NOT GeoMark enabled since we no longer use Terrago software to produce our maps. Some of the capabilities of the Terrago Toolbar are now included in Adobe Reader, and The National Map Viewer (which has seamless contours) has far more capabilities.
- Video Lesson 8a: US Topos Created after June 2017
- US Topo Map Users Guide
- US Topo Map and Historical Topographic Map Users Guide