Can I still fight a traffic violation I received in OKLAHOMA in 1999 & NEVER went to court over, or paid?

If the violations happened ten years ago and are still active, i.e., there is a warrant for your arrest for Failure to Appear, you still have a right to your "day in court."  But, because the offenses happened so long ago, you can say your constitutional right to a "speedy trial" has been violated. Especially if you haven't changed addresses or otherwise made yourself unavailable, the charges could be dismissed, but you'll have to file a motion in court for that purpose. Any attorney will know how to do this. Or if the prosecutor is reasonable he may agree that the charges should be dismissed in the "interest of justice."  I certainly would not plead guilty, even if it's for a failure to appear. The police must do something to find you during that period. Meanwhile, go to the clerk's office and ask if there are any warrants for your aresst.  Many courts nowadays will be you that information via their internet free of charge. Maybe they didn't file any charges against you.