I grew up skiing Sunshine Village along the Alberta/British Columbia border. There's a lift called the "Great Divide" where the rider apparently starts in Alberta, crosses into BC, and then returns back to Alberta before reaching the top.

As you ride up, you're greeted by a sign that reads "Welcome to beautiful British Columbia", and then "Welcome back to sunny Alberta". My Dad used to always joke about the snow melt either traveling to the Hudson Bay, or the Pacific Ocean depending on where you are along the lift line.

Had to test it out for myself. Unfortunately the lift doesn't quite carve across the watershed boundary as I hoped, but it's very close, and it was fun to wonder about as a kid.