Just an FYI, OCI = "on campus interviewing" so if you were at an off-campus job fair, it wasn't OCI.
I'd start with a Martindale search on Lexis, or you can also get some firm names from the state bar association website. Additionally, career services may be a good place to start as well, in terms of providing you with some firms or pointing you into a good direction on where to look to compile your list.