Lost Senior Golden Retriever - Help Find Cooper!

He is a 10 year old male red haired golden retriever I was working outside and forgot to close the gate to our yard when l let him out i went back to check on what i was cooking about 10 minutes went buy so i hollered for him he didnt come that’s when i realized he was gone i started looking for him by myself at first buy 7:30 their was about 10 of us it was like he just vanished his name is Cooper