How do I make a road map from individual Google paths?

My work requires me to drive down long-forgotten and unmarked roads.  There are restrictions; some roads are permitted to drive on, and some are not.  As such, my field guys have created a Google Earth package of paths that list all the available paths to drive on.  I want to take all these "paths" from Google Earth and turn them into a map on my Garmin Montana, so when I go from point A to point B, I can either follow along the map, or get an actual route from the Garmin.  I really don't need the routing capabilities, but it would be nice to have just one file/map.

I have saved Tracks, and I can click on them individually to appear on the map, but this is tedious.

Is this possible?  How would I take paths from Google Earth (and there are about 100; the guys made all these little individual things) and turn that into a map?

Thank you for your help!

-m