Making your own Garmin Maps
After making the change from a Magellan eXplorist 210 GPSr to a Garmin GPSMAP 60CSx, I soon realized how much I valued the street maps I had purchased for the 210. Although I didn't use the street maps to do cache-to-cache street navigation, it was a great reference tool to see how to approach the cache from the road and what obstacles might be in my way. I was surprised to stumble across a website detailing how you can create your own maps for various Garmin GPS units using freely available data and freeware or shareware applications. Now, you can purchase the pre-packaged Garmin Maps for your GPS unit, but where's the fun in that?
Websites with the Data
USGS Hydrological Database - This website hosts extremely accurate hydrological (water) data which includes lakes, rivers, and streams.
USGS National Map Seamless Server - This website hosts very accurate topological data, as well as road, railroad, and National Park data.
Software You'll Need
Dem2Topo IDL Application - Dem2Topo is an application written to create Topographic Contour data from the GeoTiff files downloaded from the USGS.
IDL Virtual Machine - Dem2Topo is written in IDL, and you must install the freely available demo version of the IDL Virtual Machine for it to work.
GPS MapEdit - GPS MapEdit is a great application used to create your maps and their various layers.
cGPSMapper - The utility that will convert the GPS MapEdit maps into Garmin maps.
MapSetToolKit - A great front-end utility for cGPSMapper to load your converted Garmin maps into the Garmin Mapsource software.
The Process
Step One - Downloading the data
Step Two - Rendering the Topographic Data
Step Three - Creating the Maps in GPS MapEdit
Step Four - Converting the Maps into Garmin Format
Step Five - Loading the Maps into Garmin MapSource