Installing multiple img's on Oregon 450 in GPS technology and devices Posted September 23, 2013 I understand what you are wanting to do and why, and agree with your reasoning. I just don't do it by turning individual maps on and off, I essentially do the same thing manually for the same reasons. (Winter trails are not the same as Summer trails in the same area.) I group "sets" of trails in different gpx files. Grouped by season or area or type or??? and named accordingly. I place the appropriate gpx file(s) on the memory card. The individual tracks in the gpx file show up in the Track Manager tracklist. User settings on your gps determine whether or not individual tracks are "show(n)on map" or not. Word of Caution Note: Let's say you have 20+ named tracks in one gpx file on the card. All the track names will show in the TM tracklist and if you have so designated, all will be displayed at the same time on the map. Now, if you archive one of those 20+ tracks for some reason, it is removed from the gpx file on the card and put in "archive". Even if it is later "remade" a Favorite, it does not go back into the gpx file on the card. (it is then/now stored in internal memory) That "card" gpx file is permanently modified. Knowing that, I only add,remove,edit data in the "Master" gpx file for that "system" on my PC, and then just copy it to the card and let it overwrite the old file on the card. If you see duplicate named tracks in the TM tracklist, it's probably because one is coming from the internal memory and the other is coming from the gpx file on the card. I delete the one from internal memory because I try to keep the "Latest & Greatest" info up to date in the PC ver. gpx file. I only have to worry about keeping one file per "system" (or however they are grouped) updated. All (and only) pertinent data is included, waypoints, tracks, routes,etc. because intersection points sometimes change with the seasons also. You're in control of whether you put only one gpx file on the card or multiple files. If it's on the card it's data is available, if not ....DUH...it's not.