Cell Phone Signal Strength in Banff Tunnel Mountain + others

There is no cell coverage on the Icefields Parkway from Hwy 1 to Jasper. You will pick up service about 30 kms south of Jasper. There is good cell service at Whistler's Campground, but no wifi.

There is good cell phone coverage from Cranbrook all the way to Raduim Hot Springs. In some places it does fade out but not for very long. We make the trip from the Kootenays to Calgary through Fairmount and have always found we had good service.
There is talk about putting cell service through Kootenay Park however haven't been through since mid Feb, so not sure if it has been installed yet. When you pop out at Castle Jct onto Hwy 1 you will pick it up usually pretty quick but weak, and good service by the time you hit the turn off to Sunshine Village
Soup

Fairmont Hot Springs has good cell coverage. There is also wifi at the campground. Coverage depends on where your site is. The wifi antennas are on top of the washroom buildings.

There is good coverage at Tunnel Mountain Trailer Court. I'm heading to Jasper tomorrow ( Whistler's campground ). I'll post when I get there.