Sentry Box in Prince Albert during Rebellion (some question as to info)

The individual in the photograph is on guard duty at a sentry post at Prince Albert, NWT, 1885. A few possibilities exist for what this photograph represents. It appears to be a Northwest Mounted Police man (note the pith helmet), or less likely, a member of the Prince Albert Volunteers, or the Prince Albert Home Guard taken during the "siege" of Prince Albert. Another possibility is that this man is one of General Middleton's regular forces from the Northwest Field Force, who marched onto Prince Albert following their victory at the Battle of Batoche to relieve the town from its percieved state of siege, before heading West to pursue Big Bear and Wandering Spirit's Cree.