Hi Julie,
As Julia intimates, there’s no bad time to visit The Rockies ..
I was there in late June when the weather was glorious. The mountains, lakes, rivers, waterfalls, views, wildlife, towns and food equally so. Absolutely loved Banff and the surrounding area.
Dave’s and Mike’s Reviews of their winter trips paint a totally different landscape, but one that has me very keen to experience (maybe early ‘21) as a result.
Whichever you decide to do, I’m sure it will amaze and delight. Spin that coin !
Regards,
Roger