Slice: North Idaho/Northern Idaho?

“Regarding the North Idaho/Northern Idaho debate,” wrote Shannon Bahr-Allert. “When I was visiting Pocatello last summer we were watching the local TV station and they refer to ‘Eastern Idaho’s biggest Ford dealership’ or ‘Eastern Idaho’s best weather coverage’ yada yada yada. I turned to my friend and said that up north we refer to Eastern Idaho as ‘Montana’ ”/ Paul Turner , The Slice blog.

Question: Who should decide whether it’s North Idaho or northern Idaho?