Coeur d’Alene … In Western Idaho?

Spudbob sends the following email: “I am reading a fascinating book called, “Cadillac Desert, the American West and its Disappearing Water” by Marc Reisner.  I just got to the chapter that deals with the Columbia River and on page 160 I came across this interesting sentence, “Near the present location of Lake Coeur ‘Alene in western Idaho” [emphasis added]. Shucks.  Up to that point I was believing every single word he had written but now, I am not so sure.  I suppose we should be pleased to not be mistaken for Iowa or Ohio.”

Question: Where would you put western Idaho?