Golden retriever with red collar missing in Stillwater

I lost my golden retriever, Rusty, yesterday around 3pm. He wears a bright red collar with a small blue tag that reads 'Rusty' and has a white patch on his chest. We were near the Stillwater Riverwalk behind the OSU football stadium when he spotted a squirrel and bolted after it; he's friendly but can be shy around strangers, and he weighs about 65 pounds. He's microchipped, so if anyone brought him to a vet or shelter, they can scan him. I'm really worried - he's been a part of our family since I adopted him as a puppy, and he's got a sensitive stomach. If you found him, please text me; I'd be so grateful.