Post an outdoor sign like the kind you'll find at BiMart for garage sales at each intersection. Also drop off fliers at local vets and shelters. There are quite a few so don't just go to one. There is a list available at the SW Washington Humane society that you can use as a reference. Post on Nextdoor. There are a lot of veterinarians so focus on the 24 hour emergency ones first and then work your way down to local clinics. Post fliers at major grocery stores in your area. And don't give up!
Is your dog chipped? Licensed? Call Humane Society.
Also if you have a facebook, try to find a lost pets page and post in there
Thanks! Your answer is awaiting moderation.