Cy,
Excellent.
Just a few comments:
When opening the foothills.kml file in Google Earth. I see the spinning globe and the foothills trail data showing up in the Carolinas, but the globe continues to rotate and stops over Africa, which is strange but could be my settings.
When I fly back over to the Carolinas, I see the track boundries box which is something new for me and easy enough to turn off.
It took me a minute to figure what was going on with the tracks and routes. I decided to turn off the track "points" and a nice line remained.
The "routes" are an artifact of the origional ExpertGPS file and I will will probably eliminate them from the published data.
Conclusion: you have taken a very detailed GPX file and made it into a nice KML file. The reuslt is an excellent hiking trail presentation in Google Earth.
My complements,