Rabbit Ears Garmin Maps
I used to use the overlay .kmz image method. However, the maps never really line up with the GPS due to projections and such. I have a .kmz for Rabbit Ears and North Routt, which are decent approximations.
After getting frustrated with those, I started down the path of creating actual Garmin maps that you could load into BaseCamp, onto your handheld, etc. It turns out that even if you have the requisite data, creating maps is non-trivial. And one of the key programs seems to have recently disappeared off the 'net meaning I'm using another program that isn't yet as fully featured, so working through that.
So far I've got the Rabbit Ears area for Steamboat Springs, CO, created. It shows the non-motorized and permit backcountry access areas, as well as has all the groomed and ungroomed trails. It has no topo features, one would have to get your own topo maps and overlay the trails on top of that.
The maps themselves are accurate, but there's plenty of minor details that still need to be cleaned up, everything from copyrights to getting the name of the map to show up correctly on the device, but at least the data is there and labeled.