Did you get a chance to talk to either of the teen groups hiking in that area? My bet is that it was a group from the Wilderness Trail organization, a Methodist ministry that has a basecamp down at the bottom of the mountain in Troutville. I've hiked that section many a time with a herd of kids in tow, although since my daughter went off to college I've yet to be back. I love the idea of the blue blaze trails as it can get crowded in the Mt. Rodgers area. Great trip report!