You're asking for data on one of my favorite places! I rode at East Fork
for many years and served with the Mounted S&R there. Wonderful place!, the Red Fox Trail
is my fav!
Trail maps that you can upload into a GPS are available for some areas, unfortunately not all. You can find a free printable map for East Fork's
horse trails, (the north side of the park) HERE
I'm working on exactly what you're asking for through TrailMeister.com
to offer in addition to the free printable trailmaps that we already have. We should have a beta feature for the downloadable GPS maps in month or so. We'll be supporting Garmin products initially.
If you're interested in being a guinea pig and verifying the validity of the data transfer into your GPS, your help would be much appreciated. You can contact us by visiting www.TrailMeister.com
and sending us a note through the contact us page.
Hope this helps and happy trails!