For mule bucks or mulies & goats I personally like to hunt north of I-94 between the North & South Units of TR Park. If you're more interested in goats, generally speaking I would suggest south of I-94, from Amidon & south from there...
One thing about ND as opposed to Montana or Wyoming; you won't see the sheer numbers of goats, but proportionately you will see a lot of P&Y bucks...
3-4 point mule bucks in the 24"-26" range are pretty common, with the occasional 26" plus to raise your blood pressure...
Don't discount the whitetails out there. three of the five biggest whitetails I've seen on the hoof in my roughly 30 years in ND, I saw out in the Badlands...