Drag Rider:
The drag rider is as it sounds, one who rides the drag or rear of the group. Sometimes called a duster. They also have responsibilities. One of these is to look ahead into the group to spot any potential problems. This is a needed position as the trail boss should be looking ahead and to the sides, because you don’t want a trail boss riding backwards. They have the vantage point to see if someone peels off the group into a detour or different area.
They may be the last person to see a discarded or dropped piece of equipment. In certain situations, they may be more able to reach a trouble spot in the group before the trail boss, seeing how they may spot it first and are already headed in that direction. They have the responsibility of closing gates or replacing other items that may have been altered to let the group through. As well they may hang back as guides for rescue/service vehicles, or riders at access points. This should be at the last access point to let them know which direction to follow.
A drag rider should maintain a position at the rear of the group as half way up into the group nullifies his effectiveness. Exceptions, of course, would be horses that can’t have horses behind them, etc., (another point on this later) at which time they may ride closely in front of them or drop far enough back to not be a hindrance. In the event of a stoppage (tack adjustment etc.) they should remain with the last rider until such time as they catch the group. In this event, or the event of them hanging back as guides, an outrider can temporarily take the last position in the main group.
The outrider can also act as a voice of the trail boss for those more to the rear of the group. While the drag rider tries to keep everyone in front of them it may not always be possible. At such times they should strive to keep both the last rider and the group in sight at all times.