I've just got back from Canada this morning and am reading through the posts that came in while I was away.
The helicopter flight was beautiful and not at all scary - each one takes 5 passengers and the views over the Rockies were marvellous. I was very firm before I went that I would NOT do the rafting but Brian, our Tour Manager (who, by the way, you will almost certainly be having in September), described it as "rafting for softies", not "white water", and on the basis that I'd never done anything dangerous in my life so far I signed up for it. It was great fun, if a little damp around the nether regions at times, and apart from a sore arm where I clung onto the side rope for dear life while my fellow passengers seemed to sit nonchalently) I thoroughly enjoyed it, as did the rest of us. It didn't clash with the nature walk because we went rafting in the afternoon and walked in the evening. The only excursion I didn't do was to the Columbia Ice Field - I walked on a glacier some years ago and hated the feeling - but the ones who did go seemed to have had a good time.
One tip - take good walking shoes. One of our party only had a pair of flipflops and a pair of flat leather-soled shoes, neither of which gave a good grip, which you do need on the various walks along canyons, to lakes, etc.
Have a lovely time.
Ann
