When I go to the official website, this is the extent of what I find on geology:
The Olympic Mountains were born in the sea. The basalts and sedimentary rocks that form the mass of these peaks were laid down 18 to 57 million years ago offshore, then uplifted, bent, folded and eroded into the rugged peaks you see today.
That's it. They babble on for pages about flora and fauna, but geology gets a mere mention. Le sigh.
I'm sure that we'll manage to find some geology anyway, but for those who have been there (or haven't but know bits about it), here's a chance to tell us what you'd like us to see and do. If you have a spot you want to experience vicariously, let us know! Hurricane Ridge is already on the itinerary, but I know there's far, far more. Cast your votes!