Try here:
http://airlinepilotcentral.com/airlines/regional.html

Data is usually pretty accurate and up to date.

Might want to also check the "major-national-LCC" section since some large regionals like Comair (MCO base) and Mesa* (MCO base) are listed over there.

* = this is not an endorsement by me for ANYONE to go to Mesa. I firmly believe that anyone stupid enough to go to Mesa gets what they deserve.