I recently found some old Topo maps that have been digitized. USGS topo maps from before the impoundment of most man-made lakes, some going back to 1884, but most since 1940. How could I transfer features I want from these to my Navionics map? I'd like to transfer some old road beds, home sites, bridges, etc that are now inundated. Navionics has some of them on it, but they have only scratched the surface of what was there before the lakes were flooded. I have Easy GPS Pro, but have only scratched the surface of its capabilities. Not sure if that would help. Being able to transfer these to a Nav card would make on heck of a structure fishing tool. Thanks in advance.