I originally intended on creating a page with lots of information on GPS maps info for Central and South America.. After doing a little bit of research, it seemed that this has already been done by a few other over-landers and adventure riders, so I’m not going to re-invent the wheel here..
The folks over at LifeRemotely.com did a pretty good write up of GPS maps for Central and South America:
There are quite a few options on the interwebs for free open source GPS maps, especially for Central and South America. If you don’t own a GPS unit yet read this article for some advice.
A Word (or 60) on Paper Maps: This article is specific to electronic GPS maps, but it is my opinion that nothing replaces a good paper map. Hands down the best on the planet are from Reise Know How. You can buy through US distributors, but to get the most up-to-date versions we recommend that you contact Reise directly. (The shipping from Germany isn’t that much!)
The most popular free GPS maps are from OpenStreetMap (OSM). This is the largest open source map ever created. It 150 GB of uncompressed XML data. (Gigs people, Gigs!) OSM is always the best place to start when looking for free GPS maps. There are a few things you need to know.
The easiest way to download OSM is to visit garmin.openstreetmap.nl. Just select the region you want, enter your email address, and then wait for your maps to be compiled. You will recieve an email when your maps are ready for download. In the email will be a link to a page that will list several different file types. You decide if you want an .exe file (to install in MapSource), a GMAPSUPP.IMG file (to transfer directly to your GPS), or several other options. There is a good forum post with instructions over on Horizons Unlimited.
Alternately, you can download the entire map set via osm2garmin.com. The compressed planet.osm file is currently 22 GB. Yes, even on speedy internet, it will take hours. It is possible to download only one continent or region at a time. See the OSM wiki download page for more info.
Because anyone can contribute to or alter the OSM map file, updates happen constantly. You’ll be surprised at the differences in maps over just a few months. With osm2garmin you can easily download updates when it is most convenient for you. Usually they are a few hundred megs. If you download only selected maps through another site, be sure to revisit every few months and get a new version. You will be surprised at the changes.
If you want to contribute your routes or waypoints download JOSM. This program imports the tracks from your GPS and lets you compare them to the OSM maps. You can decide how to classify the road and what to change or upload.
Other Open Source Maps
Contrary to popular belief, OSM isn’t the only free GPS mapping project out there. Frequently, when looking for that tiny dirt road to that one-horse town, you’ll need to consult more than one map. Here is a list of other free maps for Central and South America. Sometimes they are better than OSM, other times not.
CENRUT (Central America)
Proyetcto Mapear (Argentina, Chile, Paraguay & Uruguay)
ConoSur (Bolivia, Argentina, Chile, Peru, Paraguay, Uruguay)
Proyecto Ecuador (Ecuador)
Bolmap Geogroup (Bolivia)
Viajeros Mapas (Bolivia)
My Navigation setup consists of a BMW Motorad IV GPS (basically a re-branded Garmin Zumo 660) and a 32GB SDXC card with maps and music saved on it.