A website from Indian and Northern Affairs Canada:

This series of maps illustrates the historical evolution of Canada through treaty-making between 1867 and 1999, focussing on the Numbered Treaties. The Numbered Treaties were negotiated between the Dominion of Canada and the First People who inhabited newly-acquired western territories. The maps are available in pdf.

http://www.aadnc-aandc.gc.ca/eng/1100100032297