If you didn’t catch The Atlantic’s recent 12 States of America(opens in new tab) feature, it’s worth a look. Using demographic, economic, cultural, and political data, the authors categorize each of the nation’s 3,141 counties into one of 12 statistically distinct “types of place,” then look at family income over the past 30 years through that prism.
By their reckoning, Washington has nine of these 12 “states” – here’s where you can find them:

Whatcom, Skagit, Island, Jefferson, Kitsap, Mason, Pierce, Kittitas, Walla Walla
Relatively wealthy; before the last recession, saw rapid growth and increasing minority populations.
Hshd. Income 1980-2010: +$2021

Okanogan, Chelan, Douglas, Grant, Adams, Yakima
Located mostly in the Southwest; large Hispanic populations; lower incomes and higher poverty.
Hshd. Income 1980-2010: -$3854

Clallam, Pacific, Grays Harbor, Lewis, Cowlitz, Skamania, Pend Oreille, Stevens, Spokane, Asotin
Tourist hubs and midsize towns where many workers live without benefits.
Hshd. Income 1980-2010: -$2447

Klickitat
Clustered in the Mountain West; sparsely populated; lower-than-average incomes.
Hshd Income 1980-2010: -$1675

Ferry
Heavy populations of African Americans and Native Americans; lower incomes and higher poverty rates.
Hshd Income 1980-2010: -$739

Lincoln, Wahkiakum, Columbia, Garfield
White and rural; sparse populations; an economic base of farming and agribusiness.
Hshd. Income 1980-2010: -$2765

Thurston
Located near military bases; middle-income; filled with soldiers, vets and their families.
Hshd Income 1980-2010: +$945

King, Pierce, San Juan, Benton, Franklin
Higher-than-average family income and educational attainment; closely divided politically.
Hshd. Income 1980-2010: +$3716

Whitman
Younger demographic; lots of college students and people starting postgraduate careers.
Hshd Income 1980-2010: +$669
And while these three “states” can be found elsewhere in the U.S., you won’t find them here in Washington:

None
Lower median incomes; full of young families and evangelical Christians; driven by cultural issues.
Hshd Income 1980-2010: -$1076

None
High-density, young, and diverse, with many rich and poor.
Hshd Income 1980-2010: +$2313

None
Older and less diverse than average, with lots of retirees and Boomers on fixed incomes.
Hshd Income 1980-2010: -$1003