DNRGarmin is free software produced by the Minnesota DNR. It communicates with Garmin-brand GPS units so you can move point and track history files from your GPS to your computer and back. It has the added benefit or being able to read and write files in several other formats, most notably .kml (Google Earth), .gpx (Garmin), and .shp (ESRI shapefile, usable in ArcGIS).

To use DNRGarmin you will need a data cable for your GPS. Depending on your PC and GPS unit, you may need a USB—serial converter, as newer desktop and laptop PCs do not have serial ports, and older Garmin units only have serial connections available.

A brief, two-page tutorial on using DNRGarmin with ArcGIS is available here. Be aware this tutorial was written for use in the western Upper Peninsula of Michigan. Some modifications will be necessary for other areas of the USA or world.