I have an etrex20: I am just wanting to download good detailed topo maps of wyoming. then from that create smaller maps to download onto my GPS how do I do this? first timer.
This really should have been a separate thread, it has nothing to do with Android tablets. :)
You didn't say what kind of computer you have. Anyway, go here and download either the Mac or Windows version of the free Basecamp program
Windows: http://www8.garmin.com/support/download_details.jsp?id=4435
or Mac: http://www8.garmin.com/support/download_details.jsp?id=4449
After installing the software, choose whatever maps look interesting. I have no personal experience with Wyoming maps, sorry
http://www.gpsfiledepot.com/maps/state/wy
If you aren't sure which one to download, these are probably good bets
http://www.gpsfiledepot.com/maps/view/701/
http://www.gpsfiledepot.com/maps/view/512/
After downloading, follow this tutorial
http://www.gpsfiledepot.com/tutorials/how-to-open-maps-in-garmin-basecamp/
Follow this tutorial to send the map to the GPS
http://www.gpsfiledepot.com/tutorials/how-to-load-maps-on-my-garmin-gps-unit/
And this one to enable it on the GPS
http://www.gpsfiledepot.com/tutorials/how-to-change-which-map-is-displayed-on-a-garmin-gps/
Now get out an enjoy your new maps!