Thanks for the response DATEZZ. And thanks for pointing out that Connect has a manual upload feature. I found under Activities | Import at Connect. Navigated to the GARMIN filesystem for the device but the only file that seemed like it could be a recent track file was GPX/Current/current.gpx . I tried uploading that but the site reported it had an unspecified "problem" with the data. Not sure whether that was a site problem or that this isn't the correct file to use.
Maybe my assumptions are incorrect. I used the Trip Computer feature. Reset it before a hike, and assumed that the current.gpx file would then contain just that hike. I guess there is no equivalent on this device of a set of saved Rides or Routes. Maybe what I want to do is just not possible with the Colorado?