AKC just launched the "Coursing Ability" test for non-sighthounds. It says the Canine Partners program is eligible so that means mixed breeds can compete. You will just have to find a local club that is participating.
I believe bluegrass coursing club is haveing the CAT in Calhoun Ga at the end of Feb. That or OKIGO in Ohio would be your closest AKC clubs for the test as they have not been coursing in KY the last couple yrs. I typically drive 6-12 hours for any lure coursing events, they are never nearby.