I've often wondered why the name "Spruce" was given to these routes?
I've wondered that too. My favorite theory is based on what Gann wrote in
Fate Is The Hunter about his early experiences flying the North Atlantic as a part of what later became MATS. At that time, the US had not yet become actively involved in combat operations against Germany, but were making preparations for a major deployment of troops and war materials. Part of this included working with Canada, Denmark and Iceland to open routes to Europe through the establishment or improvement/expansion of airfields connecting the Eastern US with England. A series of these fields carried the designation Bluie and were numbered between one and eight. Thule was Bluie West one I believe. Anyway, that's as good a theory as I've ever heard, but of course I'd appreciate knowing the whole story if it's out there. As for "spruce", it's quaint isn't it?