Where does Portable Maps Data come from?

[Ryan O'Brien]

Thank you for a great product.  Been using GPSE for a while now across multiple devices mostly for creating local trail maps.   More recently for mountain bike and other exercise navigation. 

I'm using v 4.4.64 for android and I see all kinds of local trail data in GPS Essentials which doesn't show up on Google Maps or Earth.  I use Google Earth to measure and save exercise loops.  It would be really great if I could get the local trail data from GPS Essentials into Google Earth.

Any information you can provide as to where I can acquire the local track data would be extremely helpful (Exeter, NH).