Lost blue dog collar with bone-shaped tag engraved with dog's name 'Rex' and owner's phone number near a park in Western Illinois.

I lost my dog's blue collar while we were out for a walk near the park in Western IL. The collar has a bone-shaped tag attached that has my dog's name 'Rex' and my phone number. I'm really worried since he needs it when we go out. Please let me know if you find it!