TenOC,
The last time I was at the Ice Fields the parking lot was jamb packed.
Spaces at the Lake Louise campground are not cheek by jowl. It is bear protected by an electric fence.
Lake Louise does have an overflow campground down the road towards Banff on the south side. There are no services. It is not free.
There are two gas stations at Lake Louise. The Petrocan is, in my experience ALWAYS cheaper for fuel. If you are going farther west, fill to the gills as fuel costs much more in B.C.
There is a shuttle bus from the town of Lake Louise up to the Chalet and lake. I think it make stop at the campground--but I can't remember for sure.
Banff is a tourist trap with prices that reflect that. I much prefer Lake Louise.
Where will you be coming from?
