Re: Closest place to Oklahoma for some steelhead ?
As has been stated, the Lakes are closer, but if you're going to do it you should probably head for Idaho. There are three steelhead rivers, and they get going in late September. The Clearwater, Snake, and Grande Ronde.
Of course, your other option, and the same distance as Idaho is Northern California. The Russian River has native steelhead (and really good wine), and if you go north of there you have the Trinity and Eel, among others. Id check it out.