Heavy clouds and intermitent rain (sometimes even snow) in summer is normal for the Canadian Rockies and, for a Californian like me, mid-summer there can seem like mid-winter at home. But when the clouds break up and the sun comes out it is all the more glorious.
On my 1997 trip to Banff and Jasper this is what happened - I had one half-afternoon of good weather out of a week. Luckily it coincided with my hike up the short steep trail on Parker Ridge, just south of Sunwapta Pass on the Icefields Parkway.
The trail swithbacks up the northeast side of the ridge, then crosses over and runs level to this incredible viewpoint. The U-shaped canyon below is floored with outwash from the Saskatchewan Glacier, an outlet from the huge Columbia Icefield. A hunded years ago the glacier extended down past this viewpoint, but alpine glaciers have been shrinking for decades, and it is now visible far off at the top of the valley.