Site

State

PM AQI* (ug/m3)

Winthrop-Chewuch Rd

WA

115

Twisp-Ewell St

WA

75

Oroville-1117 Main St

WA

46

Colville-E 1st St

WA

32

Pomeroy-Pataha St

WA

23

Clarkston-13th St

WA

21

Omak-Colville Tribe

WA

20

Enterprise - US Forest Service

OR

19

Dayton-W Main

WA

19

Cove - City Hall

OR

15