I can't believe Dow hasn’t posted yet; he must be out climbing.
Dow is the man for Canadian Rockies rock routes; apart from local guides, few locals have climbed as many multi-pitched rock and alpine rock routes as Dow. Dow has bagged many non rock summits as well.
Myself, I have close to 300 Canadian Rockies summits over the last 15+ years, mostly walk ups, but also half of the 11,000’ers and many glacier and easy rock routes (5.4 to 5.7). Depending on your objectives, the Canadian Rockies can be very busy on the famous routes, or you can have entire river valleys and complete ranges to yourself.
Any route, close to the highway, in good weather, and of quality will be very busy on the weekend. Many high quality routes exist within a few hours walk along well maintained trails and where most times you will be the only party on the route.
The weather plays a huge part in the quality of most routes, like most mountain ranges
The winter of 2010/11 had record snowfall and Alberta/BC had a very cold wet spring. Even with the best summer we have had in years, many alpine routes are in tough (snowy) conditions, but many glaciers and ice faces have the best coverage they have had in years. It is typical in the Canadian Rockies to get snow every month of the year above treeline, especially north of Lake Louise.
Usually, July and August are the best climbing months and have the most stable weather; or it can rain (snow above treeline) for the entire month of August. The best current guide (although old now) is Sean Dougherty’s “Selected Alpine Climbs in the Canadian Rockies”. Maybe out of print?http://rmbooks.com/book_details.php?isbn_upc=9780921102144http://rmbooks.com/book_details.php?isb ... 0921102144
Some locals, unfairly in my opinion, refer to this guide as the book of lies because of some lack of detail or misinformation regarding a few routes in the guide (likely routes the author did not climb). Considering the variety of routes, the geography of the region, the book is quite extensive in its coverage, but of course experience and skill of the user is still required. (I think Dow is going to disagree with me on this recommendation)
I have only climbed a handful of peaks in the Purcells, and no peaks further west, so I cannot comment much on those ranges. Everyone I know who has climbed in the BC Cascades and Coastal ranges loved it, but access can be a challenge.
Sheelba, if you are keen on the Canadian Rockies, pm me and I provide more information.