Ramifications in CO are contempt of court and 6 months of potential jail. The best way is to get the OR Department of Social Services or OR Family Support Registry to go after him for the collection of child support and arrearages. They will revoke his driver's license in all likelihood until he starts paying current child support and has made at least three payments on back child support. You can transfer the case to CO and they will likely pursue the same paths for you.
The information provided in this answer does not create an attorney-client relationship. If you are interested in his legal services, feel free to call Chris at (303) 409-7635 at his law office in the Denver Tech Center. All initial consultations are free of charge.
In addition to the excellent advice of Mr. Leroi, I submit the following: If the support order, decree and other orders in your divorce have not been domesticated in Colorado, you should arrange to get all documentation necessary to do so. It is difficult and expensive to litigate at a distance, and you have every right to Colorado taking jurisdiction under the Uniform Child Custody Jurisdiction and Enforcement Act (UCCJEA). As for payments affecting his ability to interact with your son, he currently has all the rights granted in the original divorce. Payment won't change that, but moving for modification of visitation (parenting time) will. You could ask that the father, at his expense, complete counseling and then have counseling with your son prior to establishing any visitation schedule. You could ask that all visitation occur in Colorado, as it is an estranged relationship. This usually results in the father not pursuing visitation. I do not know the full scope of assistance available through the Child Support Enforcement Unit (CSEU) in your area, but you should contact them as soon as possible so they can coordinate with your lawyer to proceed. The more CSEU does, the less your lawyer has to do, and CSEU is free. Good luck.
The information provided in this answer does not create an attorney-client relationship. If you are interested in his legal services, feel free to call John at (970) 544-6470 in Aspen. All initial consultations are free of charge.