I'm also in Oklahoma and just getting into F-Class shooting. As No.343 mentioned, OKC Gun Club seems to be a good place to shoot F-Class around the OKC area. I went to my first F-Class match there, the OKCGC Prone Championship, a couple weekends ago and it was a lot of fun! Lots of friendly people there. There were a variety of disciplines at this match (I shot F-Open) and I was told this is their largest match of the year. I attached a few pictures I took there so you can get an idea of what the range looks like here from the 600 yd line. I'm planning on shooting there regularly, so if you come out you'll probably see me there!