getting from Banff to Jasper without a car
 

I am planning a trip to Banff and Vancouver and would like to visit Jasper National Park. What is the most economical way that I can get back and forth between Banff and Jasper without renting a car? Also, can I book something that also takes me to the Columbia Icefields?

You can hitchhike. The only place in the world I have ever done that is in Jasper because I have never felt unsafe there. Not that I am recommending it!

If you are staying in a hostel, or even if you just drop in to the hostel, you will probably find someone with a car who is going that route.

Otherwise, there is a bus service. Try this link for information (including travel to the Icefields):
http://www.jaspercanadianrockies.com...ation.html#Bus

Brewster coaches run an airport shuttle service that runs Calgary to Jasper with stops in Banff, you will probably be able just to book the leg between the two.

Also Brewster run a sightseeing trip between Banff and Jasper which includes stops at Peyto Lake and the Columbia Icefields. You can buy a ticket that also includes the Snocoach for the trip onto the glacier/

I think their website is www.brewster.ca