Site

State

PM AQI* (ug/m3)

Maple Falls-Azure Way

WA

42

Butte (Harrison Court)

AK

41

Portola

CA

35

Omak-Colville Tribe

WA

32

Aberdeen

SD

30

Watertown

SD

27

Fargo NW

ND

27

Mammoth Lakes

CA

26

TRNP-NU

ND

25

Detroit Lakes

MN

24