Thank you all for your help. Just to report back, here's what I did. One thing I had neglected in my initial requirements is that of the people in my club use smartphones.
I found a pretty good source of data in the form of a JPG, which I calibrated and traced using ExpertGPS (which I had from years ago).
The problem I ran in to was many of the viewing apps (mostly for smartphones) I used didn't care for tracks that consisted of multiple trksegs, in other words, resulting from tracks that branch or are not contiguous. Expert GPS also doesn't provide a way to create a single track with multiple disconnected segments. So, the original problem remained unsolved.
What I did was write a short XSLT (which is a way of transforming an XML file into a different format) to combine all segments with the same name into a single (possibly disconnected track). That way I end up with a GPX with I think 4 tracks, one for each trail type and for creeks.
So now, I've got two GPXs, one with simple tracks and another with combined tracks. GPS units like the combined ones, but I use the simple one for editing and importing into other apps.
Also, for those users with modern Garmin GPS units I used ExpertGPS to export Custom Maps with the trails traced onto aerial photos.
So, in the end, I have files that can be used by old devices (like my eTrex Legend), smart phones, and modern units. Sorry if it feels like I ignored your advice. I looked into each of them, and I enjoyed the experimentation.
After all that, I decided to look into uploading my traces to OSM after they've been validated in the real world.
I found a pretty good source of data in the form of a JPG, which I calibrated and traced using ExpertGPS (which I had from years ago).
The problem I ran in to was many of the viewing apps (mostly for smartphones) I used didn't care for tracks that consisted of multiple trksegs, in other words, resulting from tracks that branch or are not contiguous. Expert GPS also doesn't provide a way to create a single track with multiple disconnected segments. So, the original problem remained unsolved.
What I did was write a short XSLT (which is a way of transforming an XML file into a different format) to combine all segments with the same name into a single (possibly disconnected track). That way I end up with a GPX with I think 4 tracks, one for each trail type and for creeks.
So now, I've got two GPXs, one with simple tracks and another with combined tracks. GPS units like the combined ones, but I use the simple one for editing and importing into other apps.
Also, for those users with modern Garmin GPS units I used ExpertGPS to export Custom Maps with the trails traced onto aerial photos.
So, in the end, I have files that can be used by old devices (like my eTrex Legend), smart phones, and modern units. Sorry if it feels like I ignored your advice. I looked into each of them, and I enjoyed the experimentation.
After all that, I decided to look into uploading my traces to OSM after they've been validated in the real world.