It seems like Garmin files work only with Garmin GPS units and the same goes for Magellan. There's probably a program that converts for either. I've tried to save and send tracks in a file that's supposed to be compatible with either mfg's but still didn't work for the Magellan user I sent it to.
I think there are more people with Garmin GPS units than Magellan's, but I could be wrong. I have a whole bunch of tracks saved from my Garmin GPS, so if there is somewhere you want to go, post it up and I'll see if I have the tracks for that area.
There is a
United States Topo program that I use. It's around $100 or so. It is comparable to the US Geological Survey's 1:100,000 scale paper maps. There is also
US Topo 24K National Parks maps in which I have the NP West maps. Both programs are very detailed and they have worked very well for me.