Up until a few months ago I only ever used Yahoo, MapQuest, & Google for my mapping needs.  In fact, I got rid of all my old paper maps years ago.  Why bother when you can just download the map you need & print it off?  And with smart phones now you have the maps with you.  That's one of the main reasons I never bought a GPS unit for my car.  I figure why bother whn I have a map function built into my iPhone?

But ever since buying my Garmin eTrex Legend GPS for going geocaching I've realized there are many more map options out there for different purposes.  The Geocaching.com website and iPhone app have different options for different types of maps.

Street Maps
Just what you think they'd be: maps of streets.  However, different websites provide different details and different levels of accuracy.  I find Yahoo & MapQuest to be more accurate with where an address is located on a street.  But I find Google has more recently created streets.  This time the Geocaching website & app chose to use Bing, Google and OpenStreetMap.org (OSM).  OSM is an open source mapping system.

Sateliette Maps
Sateliette maps are actual images of the area taken at different levels of magnification.  Depending on the website or service you use depends on how recent the images are and their level of magnification.  The Geocaching website and app use Bing, Google, & Google Hybrid (Google Street Maps overlaying the satelitte images).   Since I don't need extreme detail or recent images I use these free versions too.

Topographic Maps
When hiking, camping, or doing anything outdoors it's always helpful to know ahead of time a lay of the land.  You need to know when there are sudden or gradual changes in elevation or the type of terrain you'll be going through.  Topographic maps use lines to show you changes in elevation.  So the closer together the lines the steeper the terrain.  This time the website and app use OpenCycleMap.org (OCM).  OCM is also an open source mapping website.  However, this one is geared (hahaha!) towards cyclists because with topographic maps they can know how many hills are on their planned route, how big they are and how steep they are.  Of course, it also comes in handy for hikers and geocachers.

So far I've been talking about free mapping solutions.  However, there are many proprietary mapping solutions too.  A perfect example of this are maps for GPS units.  Most GPS units come preloaded with a set of basic maps.  Depending on the manufacturer, model, and purpose you can upgrade your maps for free or for a fee.

Well the base map on my Garmin eTrex legend unit is basic.  I mean so basic it only shows MAJOR highways.  I looked up the cost of the highway maps for the Garmin maps North America and they are being sold for about $100.  That's more than I even paid for my GPS unit.  So I started looking up ways I could upgrade my maps for free.

In my searching I came across a page on the OSM wiki page about creating your own maps in Garmin format from OSM exports.  I was able to download the image tiles I wanted (thanks to OSM user computerteddy).  Then using the command line program CGSMapper SendMap Pro I was able to create a Garmin compatible IMG file.

But when I tried to use the SendMap tool to actually send it to my GPS unit it wouldn't work!  I think it's because the tool is looking for a USB connection instead of a Serial connection (which is what my unit uses).  So I'm going to dig out my USB-Serial converter to see if that works.  I also noticed that one of the pages mentioned that I need to change the connection mode my GPS is using.  But there is no USB or Serial mode!  Grrrr!!

Anyone know what I'm missing?  Or is this just an impossibility with my model of GPS unit?