Just put 146.52 in your radio...oh wait that's Oklahoma City... (actually most of the activity seems to have moved to 144.98 simplex lately).
Sometimes club websites do have club repeaters, but there are quite a few repeaters that don't have clubs (confused yet?).
I would just suggest "searching" from 144 to 148 and 440 to 445, as 97.4285% of the VHF/UHF stuff in Oklahoma will probably be in those two ranges. Yes the database does ome some frequencies (usually only one per county, which might be all there is truthfully), but it normally does not include other ham stuff that might actually have more activity. The purpose of the RR database is not for hammy stuff - there are other websites for that (artsipub, etc...)
But really, 146.52 is the National 2m calling channel - you'd probably just have to listen around OKC to hear what the above comment was about...