DNRGarmin is used to convert ESRI .shp files to GPX if using DeLorme Topo or Maptech Terrain Navigator Pro.

 

This is a limited description for GIS people: http://gis.nwcg.gov/documents/gtgdocuments/GTG_Newsletter_Spring%202009.pdf

 

Preferred: Using DeLorme XMap is preferred over DeLorme Topo because ESRI .shp files can be imported directly without conversion.