Why can't I load Garmin Topo 24k and the custom ATV map file dowloaded from here

[freeagent]

I have tried to load the 24k topo and the WV trail map downloaded from here, but my Oregon only takes on or the other.  We want to see the WV ATV trails overlayed on the 24k topo.  How do we make this happen?  Thanks!

[Indrid Cold]

this map?:
http://www.gpsfiledepot.com/maps/view/500/

[maps4gps]

Garmin's software (Mapsource and BaseCamp) send the selected data (quads/segments) to the GPSr and/or micro memory card as a file named gmapsupp.img.  If a file by that name is on the GPSr or micro memory card it will be overwritten.  On the 'newer' unites, like your OR, rename the gmapsupp.img file to a filename with a .img extension, i.e. topo24k.img.
Then do the same for data from additional mapsets, i.e. wvatv.img.

OZ - Is this explained in a tutorial? 
The tutorial on 'How to load Maps on my ....'  explains how to send data from mapsets as a single gmapsupp.img.  Many have found that on the new units the component mapsets in a gmapsupp.img file can not be enable/disabled individually.   

[Seldom]

From the BaseCamp tutorial:

Note: Each time you load maps to the GPS it will erase all maps on the GPS except for the basemap (Navigation map on the Nuvi).

Looks like -Oz- needs flashing red letters for this and for more flashing red letters in another branch to cover multiple IMG files on OR and later handhelds.

Just out of curiousity, can one do mulitple IMG files on newer Nuvis?

[Boyd]

Yes, all the newer models (starting with the Nuvi 1200/1300/1400 series) recognize multiple .img files on the device. However, they need to be placed in a folder named Map at the root directory of either internal storage or a card. Mapsource is actually smart enough to do this and will create the Map folder if needed.

[freeagent]

Everyone thanks for the comments.  When you say root directory do you mean the window that opens up and shows all the folders on the device?  When I plug my unit in and open the drive (Garmin Oregon) to view files, here is what I have:

Documents Folder, Garmin Folder, Wherigo Folder, .ColumeIcon.icns, autorun.inf.

Under the Garmin Folder there is:

BirdsEye, CustomMaps, CustomSymbols, ExtData, Filters, GPX, JPEG, Profiles, RemoteSW, and Text Folders, .Position.gpx, fs_image.ver, GarminDevice.xml, Garmintriangletem.ioc, gmapbmap.img, gmapbmap.sum, gmapsupp.img, gmapptz.img, startup.txt, system.xml.

[Boyd]

The gmapsupp.img file inside the Garmin folder will be the most recent map that you have sent to your Oregon. You can confirm this if you like by looking at the file modification date. So, to follow the instructions that maps4gps has given, change the name of gmapsupp.img to whateveryoulike.img. Now you can send another map and repeat this same procedure as often needed to send multiple maps.

[freeagent]

Thanks all!  I got it!!!

[JohnCNA]

Double and Triple thanks!  As a new Etrex 30 owner, I was stymied with the same thing.

I downloaded several maps from here, but I was ending up with only 3 maps showing on the Etrex at any one time; the included basemap, one topo map and MyTrails. Trying to replace the 'missing' maps would show the last one downloaded but it removed the previous maps. I contacted Garmin support and got a reply that it must be a problem with the maps themselves; please contact the supplier of the maps.  Duh. Well, actually, they were right. I found the answer from the source of the maps. 

How easy to just download one at a time and rename the supp map file when you're done.  Thanks again!