Obviously, the Valley is its own thing. However, beyond that it's really just a spectrum from urban to rural. There are thriving startup scenes (or at least established companies with passionate technical culture) in virtually every LARGE American city (e.g. New York, Chicago, Atlanta, etc).

There are also strong scenes in certain midsize markets that buck the larger trend (e.g. Austin, the North Carolina triangle, etc).

However, if you are in a midsize or small market outside of that handful of exceptions... then there are either few tech job opportunities at all, or the only jobs available are "line of business" type work that no passionate developer wants. It doesn't matter if you're in Memphis, Tennessee or Syracuse, New York. The problem isn't regional, it's market size.

Whenever I hear people griping about technology and "The Bible Belt", etc... I picture people fresh out of school who have never been anywhere and spend WAY too much time trading political memes on Reddit. Nonsense. There are plenty of technology hubs in large Southern cities, and plenty of backwoods hicks in the Pacific Northwest.