From an email I received from Tamarack Outfitters:
The Chief Mountain Shuttle is running again this year! First time since 2019 we are very excited to be able to offer this service again.
It is $50 CAD per hiker plus tax.
Runs at 10:30 AM and 2:30 PM departure times from Waterton.
11 AM and 3 PM departure times from the Border.
Bookings are required.
It will run until the border closes Sept. 30th.
We can occasionally accommodate Custom Times and will charge a custom rate.
You can now book the regular times online, Click HERE to Book.
https://watertonshuttle.checkfront.com/reserve/