Moraine Lake, in Banff National Park.  This scene is depicted on the back of the Canadian $20 bill that was printed from 1979 until 1991, when it was replaced by the Common Loon in the Birds of Canada series.
<a href="//commons.wikimedia.org/wiki/User:Aude" title="User:Aude">Aude</a>
CC BY-SA 2.5
<span class="int-own-work" lang="en">Own work</span>