If you want to stay on the west side of the state and close to home try Greys Harbor County. Look for alder flats, river banks, creek bottoms, and clear cuts. Young fir groves are good cover too.
East side try Chelan, Okanogan, and Stevens counties. Blues range higher, 4000-7000 feet elevation, following the berry ripening as they go. Ruffs will be lower 3000 feet and below.
Look for berries, blue/elder/huckle... Don't pass up birch cover with soggy ground...
Look for birds on the logging roads and then follow them into their coverts...