There never was a Spine of the World supplement produced during the 1E and 2E years. You are correct that most of the details would be found in The Savage Frontier or the North boxed set. Covering the same ground and perhaps of lesser use might be Volo's Guide to the North and The Sunken Tower adventure penned by R.A. Salvatore and his gaming group, which takes place on both sides of the Spine.I don't know if there's more information about the Spine in the 3.5 releases, as I'm unfamiliar with their contents.
Same here - that's what I figured. Thanks.
Ditto post on the Michael Curtis bits. I remember there was a wizard from another campaign setting mining MIthril from the mountains up there. Annoys me that I can't remember his name now. Ugh. Senility.