A couple of Public Ranges:
Everett - Sam's Gun Shop, 11714 Airport Road, Everett, WA 98204.
Hours of Operation: M-S 9-9, Sun 9-6
Arlington - Arlington Recreational Shooting and Training Cntr, 8620 172nd St. NE, Arlington, WA 98223.
Hours of Operation: M-S 10-9, Sun 10-6
Personally I prefer Sams. The Arlington range doesn't have their FFL yet, so no rentals etc.. you have to bring your own.
There are also a number of local private ranges that would require membership to use.