I'm in the D.C. Baltimore region, and the DC-to-Dulles tech corridor and the Bethesda, MD biotech region are huge tech regions.
There's a very large small/bootstrapped tech business scene here, they just don't call themselves "startups" quite as often. Most folks I know out here get funding from SV or Boston and not the local area.
The main problem of course is that many investors (and potential board members and mentors) fundamentally don't understand how to do business in this area, where the major customer is the USG. It's been done (e.g. Palantir), but they were working off of SV cachet more than local talent. Even simple things like release schedules (which inform and are driven by development practices) are different, plus the additional processes around getting approved for use on USG systems (not just DOD!) are things that outside companies just don't really understand how to deal with.
Big SV (and West Coast) companies do have significant presences out here, but they tend to be more large "sales offices" than proper tech shops.
edit I mean, there's In-Q-Tel I guess...that's part of Palantir's early story as well...and probably a large part of how they've been successful. Understood the climate, negotiated access for them, and basically helped them navigate the byzantine environment.