I'm in much the same situation as you are, as I'm squarely in the bible belt. Memphis TN to be exact. My suggestion for finding this "startup culture" is to go to meetups, hackathons, and makerspaces. I don't know your exact location, but nearly every major city in the South supports a small but growing culture of people who enjoy building and designing new things. Additionally, these people will have connections to the actual startups that are present in that city.

You didn't ask for this, but here's a rather weak plea not to move.

Please don't leave us for San Francisco!

Why I don't feel compelled to move:

1. I feel connected to the "startup culture" via the twitter, HN, etc. I understand the desire for physical co-location but really, this is why the internet is so powerful.

2. Brain drain is a real phenomenon. You'll be leaving the bible belt a worse place.

3. You can create the culture! Be on the ground floor! I helped to organize a hackathon in Memphis (http://hackmemphis.com/). It was exhilarating.

4. This will be an unpopular opinion on HN, but I find many aspects of the stereotypical "startup culture" to be repugnant. The obsession with status. I didn't go to Stanford, MIT, Indian Institute of Technology, or even lowly Berkeley. Fuck me, right? Also, the greed and cut-throat competition.

5. There are massive opportunities that won't be visible in the somewhat insular urban environment of coastal cities.