My Golden retriever is missing

We live on 28 acres of land. My golden and mixed dog. They have a good time. Baxter my golden didn't come home today. He's almost 11. I walked so much of the land , with Loki the other dog. Loki could smell his tracks. But the tracks were everywhere. I look so long when I walked back I looked like I was drunk. Then got the side by side. We couldn't find him anywhere. If he would hear us he would come or we would hear him coming. I've put out pictures. He's 11 and he's getting old . I'm devastated. Loki could smell his tracks . I'm afraid he probably didn't make it. My late husband loved Baxter. I can't stop crying. .I heard about it.