Dennis,
I have some friends who live in BC and go to Fernie every year. I am looking into going with them this year and they told me the best (major airport) travel is to fly into Calgary, rent a car, and drive though it is a longer drive (3 hours I think). I am not sure if you can get some sort of bus which would be cheaper. If you like I can get some more details for you. Any specific questions you want me to ask?
--Andrew