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.
I think it would be easier to plan ahead for the Idaho runs on account of more reliable water levels. Those NorCal coastal rivers host winter runs, and when the rain hits they're blown out for a week or more, then they green up and fish well for a little while, then they get blown again. They can be great when you hit them right, but it's nothing you can plan very far ahead for. The fall runs on the Trinity or the Klamath might present a slightly more stable & reliable target to plan for, but those rivers are *so* *friggin* *far* to drive -- from practically anywhere -- that if you're going to go there from Oklahoma, you might as well go to better places further north.