You need to catch him and try to either find the owner or contact someone local that raises/races them. For starters, call some feed stores and ask for some names of people who own them or follow the recommendations in the link below.

He won't survive on his own, so offer water and buy some feed.

Here is a link that might be useful: Lost Pigeon

If he finds other pigeons he may well survive on his own, but feral pigeons live short lives, fraught with danger.

Often those who race pigeons aren't too enthused about reclaiming lost birds, as failure to return to their loft generally means they are not great candidates for racing or breeding. But you can try, if you can get close enough to catch him. Perhaps you can lure him into a garage or shed by offering food and water.

I have a pet pigeon, not a racer but a roller pigeon (bred to perform aerial acrobatics). She came to me as a lost bird 10 years ago and has stayed. She flew onto my front porch, and then into my house when I opened the front door. I did locate her breeder and he said I could keep her.

Thanks. I couldn't see it anywhere today. Hopefully he comes back. We tried to approach it a few times, very cautiously. My daughter would love it if we did catch it. I will keep my eye out for it and maybe pick up some bird seed to lure it closer should I see it again.