Terracing associated with catastrophic glacier collapse - observed over large spatial scales.

In 2017 a trip to Missoula, Montana, chasing the theories of catastrophic glacier collapse and the drain of the Glacial Lake Missoula (https://en.wikipedia.org/wiki/Lake_Missoula), I got this photo of the terracing or wave-cut strandlines.

Terracing on the hill overlooking Missoula, Montana - elevation 1347 m/4265 ft.

In 2019 while canoeing on Lake Windemere in the headwaters of the Columbia River, 500 km/300 miles away at an elevation of 800 m/2624 ft.

Terracing on the shores of Lake Windemere in the headwaters of the Columbia River at an elevation of 800 m/2624 ft.

Amazing that whatever was occurring to make these cuts in the banks of the Columbia River would have occurred over such a wide geographic area!