I live on the edge of this area. Coeur d'Alene, ID is at the mid upper right in that map...Spokane/Cd'A are the cities you can see by the lakes. Cd'A is at th

I live on the edge of this area. Coeur d'Alene, ID is at the mid upper right in that map...Spokane/Cd'A are the cities you can see by the lakes. Cd'A is at the bottom of what is known as the Purcell trench. It is very clear if you look at the area that this flood happened suddenly. Lots of exposed rimrock, the Rathdrum aquifer is massive and everything out here is riddled with glacial tumbled granite. Lake Pend Orielle is one of the deepest in the nation and at the North side is where the Clark fork "dam" was from the ice. When you look at the mountains where the river comes through they are fairly tall but there is a very noticeable "v" where the river comes through.[1] I would be more willing to believe something destabilized the mountain that was supporting the ice (earthquake? We do get them here). Geologically this event happened not that long ago. Scars are clearly visible pretty much in all of the area if you look close. There is some discussion as well that there are stories of this event in various oral histories of the native people but I think it is still being studied. Sidenote: Lake Pend Orielle was where Farragut naval base was...totally landlocked naval base where they still test sonar to this day. [2] Rumor has it they used to collapse subs in the lake due to how deep it was...but I am not sure how factual that is. [1] http://hugefloods.com/Ice-Age-Floods-2.html http://hugefloods.com/Ice-Age-Floods-2.html Pic here labeled "Clark fork river" shows what I mean...but small picture [2] https://en.wikipedia.org/wiki/Farragut_Naval_Training_Station https://en.wikipedia.org/wiki/Farragut_Naval_Training_Statio...