Hi ,I'm new to this site and new to the topo and gps world,I'm very happy that I found this site. I have the New England NG topo program on my laptop. First question is can I install the topo maps to my Garmin Etrex 20,I know i can install waypoint to the gps from this program and have done so. I like the maps in this program better than the one I downloaded free from this site and thank you for that, and I did load it to my gps. Second question is when i loaded the program in the computer I can read level 1-3 without the disk being in the computer but not level 4 and 5. National Geographic told me some steps to take to install it and I followed them six time and still doesn't work. I did send them another email askinf for more help
NG topo maps are copyrighted and use a different format than Garmin's GPSrs.
The National Geographic state topo series can be installed on the Magellan Triton devices (I have one of these). There are new National Geographic Maps that can be installed on the new Magellan Explorist series too. But none of their maps are compatible with any Gamin devices.
However National Geographic uses scans of USGS 24k topo maps. You can get these in the form of Garmin BirdsEye topo with unlimited downloads for $30. See: https://buy.garmin.com/shop/shop.do?pID=98816
(https://static.garmincdn.com/en/products/010-D1140-00/g/sc-05-lg.jpg)