This is Wikipedia.
(Search: ‘Blank” County Washington State)
To find your county quickly, once the link is loaded, erase the "King" from the URL and replace it with the name of your county instead.
Use this if the other link didn't give you sufficient information.
You'll need to know the major cities in your county for this website to be any use to you. :O)
Pay attention to the parenthesis which list the city of birth for each person. For this you'll need to know major towns/cities in your county.
The web version of the Jeopardy Powerpoint Study Guide for Washington State Chapter 1