From the YakimaHerald.com Online News.
Fireworks are legal in a handful of Yakima Valley towns. But local ordinances limit hours of sales and discharge of fireworks within each town, so be sure to check with local authorities whose phones numbers are listed below.
Yakima -- No
Selah -- No
Union Gap -- No
Moxee -- Yes (575-8851)
Naches -- Only at Clemans View Park (653-2647)
Tieton -- No
Wapato -- No
Toppenish -- No
Harrah -- Yes (848-2432)
Zillah -- Yes (829-5151)
Granger -- Yes
Mabton -- Yes (894-4096)
Sunnyside -- No
Grandview -- Yes (882-9200)
Prosser -- No
Yakima County unincorporated -- No
Benton County unincorporated -- Limited types of fireworks allowed (786-5622)
State and federal lands -- No
Yakama Nation - Yes, but not on private lands within the reservation. Under a strict reading of the county fireworks ordinance, only Yakama tribal members are allowed to possess or discharge fireworks on the reservation.