Loading both 100k and 24k maps?

[HeyTomato]

I have a Garmin Dakota 20. Currently I have the 100k US Topo loaded on to it. If I download the New York 24K topo, can I load that onto it as well? I'm just confused how that would work. Can someone please help me or explain?  Thanks a lot.

[maps4gps]

Yes, they both can be on the GPSr.  

If topo 100k came with the unit, just make sure it is named something other than gmapsupp.img, the use MapSource to load NY24k

If you loaded it, or part of it, using MapSource, then rename the gmapsupp.img, topo100k.img - or somename with an .img extension.  Then use MapSource to load the 24k topo, or part of it - you would not have to rename this gmapsupp.img file (i.e. NY24k), but you may as well as it would help to keep things straight in the future.

If you have not already, see: http://www.gpsfiledepot.com/tutorials/how-to-load-maps-on-my-garmin-gps-unit/

[Seldom]

It looks like the Dakota 20 has a microSD card slot, but may not have a microSD card.  I suggest you get one,  that you load your custom maps to the microSD card rather than to your Dakota 20's internal memory.  That way, if there's a glitch, you can always remove the card, or format it.

You should also backup the internal memory from your Dakota to your PC.

[HeyTomato]

Cool, thanks for the pointers. I was poking around online too and this bit of information was very helpful.
http://www.miscjunk.org/mj/mp_mapset.html

Apparently on the newer models you can select what map files you want the system to read from so they don't overlap.  I don't have my GPS in front of me at the moment, but I'm sure it's in there.

[Boyd]

The older units can do the same thing, but it's just a little more convenient on the Oregon/Dakota. But the big improvement is that your unit doesn't have any restrictions on map filenames, which is what maps4gps alluded to when he suggested renaming the gmapsupp.img file.

The older units will only recognize ONE file and it must be named gmapsupp.img. On your Dakota, you can name map files anything you want as long as they have a .img extension. This makes it easy to simply drag and drop map files to your GPS. On the Dakota itself, you will see a map screen similar to the screenshot (from the Colorado) in the page you linked to. The map names displayed there will not be the same as the filenames however. They will come from information stored inside the map file.