gps file depot

http://www.gpsfiledepot.com/

I am not an expert on your GPS unit or this site, but I was able to download 1:24000 topo background files for the entire state of montana and load them onto my e trex (well on the mini sd card anyway) There are similar files availalble for other states, and a whole mess of other things. if you are interested check it out. when I ride the machine is on and the arrow just rolls around on the map wherever I am. It will not route off the map's data, but I think it is just because it is a referenced background image of the topo map rather than a set of road, trail, and topo lines. best part... free.