The Whiteshell River is one of the major rivers in Whiteshell Provincial Park, in southeastern Manitoba, Canada, near the Ontario border. This river is close to some petroform sites that are about 2000 years old or older. The name "whiteshell" is in reference to the Meegis or cowry shells used by Ojibwa peoples in their ceremonies and teachings, especiall…The Whiteshell River is one of the major rivers in Whiteshell Provincial Park, in southeastern Manitoba, Canada, near the Ontario border. This river is close to some petroform sites that are about 2000 years old or older. The name "whiteshell" is in reference to the Meegis or cowry shells used by Ojibwa peoples in their ceremonies and teachings, especially the Midewiwin, and as recorded in their birch bark scrolls.