My list of hiking stores in Seattle:
REI (of course)
Feathered Friends (across the street from REI)
Outdoor Research factory store-- 1st Ave So, near Safeco Field.
Second Ascent-- in Ballard, new and used gear. Takes trades too. My favorite.
Outdoor and More-- check out the upstairs and back room for deals. Not too far from REI on WestLake Ave.
Pro Mountain Sports on University Ave. --- best selection of true UL gear.
Patagonia -- 1st Ave near the Pike Place Market
Federal Army Navy Surplus (down the block from Patagonia)
Marmont Mountain Works (Bellevue)
Outdoor Emporium-- more fishing and hunting, but has a lot of rain gear and DriDucks-- near Outdoor Research on 4th Ave So.
North Face-- downtown on 1st Ave, University Village too
GI Joes--- chain store. More fishing and hunting, but does carry some Marmot, Mountain Hardwear, North Face, and many accessories. LOTS of shoes.
Big 5 -- chain store, cheap accessories, often has sunglasses, watches, LED lights, knives, and shoes on sale.