Why are we still commenting on who owns what? The indigenous peoples of this country were not defeated by the newcomers. In good faith the land was to be shared.  The colonists ( 1867 and before and up to the present day) moved in, aquired? the land for habitation and their own use to make money to support their lifestyle.  Who are the "we decided" in your comment.? I suspect you mean the Government of Canada?
The Government of Canada, without consultation with the people directly impacted by their decisions has not always made the right decisions in the past. Were the Indian Act and Residential Schools good decisions? Until strong, equal partnerships are formed there will be court cases. After 150 years of abuse of power it will take many years of building trust and working together before we see an improvement in our relationship.