The Map Chooser dialog

This dialog lets you select which maps will be drawn into your map window.

• Expand Dirs: When unselected, you will only see the names of directories under the maps directory. Selected, you'll see all the files in that directory.
• Some of the buttons on the bottom can be used to select all maps of a given type, and are probably not of general interest. Vector maps are shapefiles and other line maps. The various "Topo" buttons select USGS Topo map GeoTIFF files if they retain the original names that the USGS gave them. The Clear button deselects all maps.
• Click on individual lines in the map list to select or deselect them. "Apply" will make your changes show up on your map window and keep the dialog box open. "Ok" will apply the changes and close the dialog. "Cancel" will discard any unapplied changes you've made and close the dialog.
• The Properties button opens the Map Properties dialog, which allows you to customize your map display in many ways.