The red flags are flying in Meaford over the 4th Canadian Division Training Centre.
One-thousand soldiers are taking part in a large scale live-fire training exercise called Stalwart Guardian.
Artillery units are firing large calibre guns starting at 5 a.m. until midnight.
Reservists from across the province get a chance to work with new equipment and vehicles.
The training will continue until noon on Friday with some exercises happening outside the base between Owen Sound and Collingwood.
