Golden retriever mix with orange collar

I found a dog this morning around 9am wandering behind the Wal-Mart on 41st Street in Hays, Northwest KS. It's a medium-sized golden retriever mix, about 50 pounds, with a tan coat and a darker muzzle. It's wearing an orange nylon collar with a reflective strip and a tag that reads 'Rex'. There's a small white patch on its chest and a tiny notch in the left ear that makes him easy to spot. He looked a little tired but friendly and wagged when I approached; I'm keeping him safe and hoping to reunite him with his people soon.