For those of you in the greater Southern California area there is a great map available from California Trail map: http://www.californiatrailmap.com/
It started out with just San Diego and Imperial counties but as time has gone by they have expanded north including more and more areas. It is available for Garmin, Lowrance, Android and iPhone. I ave it on my Android tablet and on my Garmin and have found it very useful.
Linear Mode
