If the divorce occured in Colorado but the spouse lives in Oklahoma, what do I need to do?

There are a few options you have.  Some depend on whether you and the mother can come to agreement or not.  Option 1.  You can file for a modification in Colorado, which would not be practical if this will be a contested proceeding requiring court appearances in Colorado.  If you were both in agreement to updating child support, then you could likely have a Colorado attorney do it with both of you signing an order but not needing to appear in person.  Option 2.  You take the Colorado order and file it in Oklahoma to be recognized and modified as an Oklahoma order.  It would need to be Oklahoma as opposed to Texas, because jurisdiction for child custody and support is where the children live. Option 3.  The child support enforcement agency in Oklahoma or Texas may be able to open a case in their administrative court and modify child support there.   There may be more facts to your situation that would affect these answers.  An interactive conversation is the best way to address all the details specific to your case.