There are"toll booths" at the entrances on the highways into Banff and Jasper where you would pay the day use fee to enter the parks. I don't know what the fees are because we have an annual pass.
If you are planning to go to any of the Canadian National Parks this year, I would order the annual pass, it is free for 2017 and is a commemorative pass so it looks different to the regular annual pass. To order go to the Parks Canada website and follow the links.
It took me 3 tries to get mine ordered because of the large demand and the website just bogged down.