Readers ask me all the time, 'I want to get out in the Olympic Mountains, but what gear is needed?' There is no right answer to that question. Variables are hiking style, goals, style of trip, season and conditions. Its important that you learn what works best for you and tailor that kit to fit those needs. The weather turns very quickly during all seasons in the PNW, so its important not to go too minimal that you are going to have a miserable trip, but only bring things you actually use. Most 'ultralight' gear lists wont fly here, unless your lucky enough to catch the weather just right.
Here is a lightweight list I put together, that combines all my suggestions on average. 
Spring in the Olympic Mountains
Backpack
Gossamer Gear Mariposa (27 oz.)
Shelter
Golite Shangri-La 3 (2 lbs. 7 oz. for fly only)
Pole (4.1 oz. - jack mod or extension needed)
Sleeping
Exped UL 7 (15 - 19 oz.)
Gossamer Gear Thinlight Pad (2.5 - 12 oz.)
Polycryo Ground Cloth (1.6 oz.)
Marmot Helium 15f Bag (2 lbs. 5 oz. average)
Outdoor Research Balaclava
Patagonia Capilene
Cooking
Trail Designs Sidewinder Ti-Tri (Use primarily Esbit fuel & Evernew .9 L pot)
or Soto Stove (fuel canister & windscreen listed)
Esbit fuel (also carry as emergency fire starter)
Sea to Summit Spoon
Lighter & Matches (carry both)
Misc.
First Aid (field stripped)
Duct Tape (small piece)
Super Glue
Headlamp
Bear Hang Cord
Soap & Foot Scrub (longer trips)
Sun/Rain
Eye Protection
Hat
Trekking Umbrella
Footwear
Luna Sandals (trail or in camp)
You! Feel free to post questions and comments below.