Slims river has stopped existing, more or less:

https://www.theguardian.com/science/2017/apr/17/receding-glacier-causes-immense-canadian-river-to-vanish-in-four-days-climate-change

Kaskawulsh glacier has receded so far that now it empties into the Alsek.

How can we try to reflect the new reality without aerial images? Remove the riverbank and add a creek to approximate the vastly reduced flow?