At this time signs are posted at Lime Kiln State Park and at the interpretive center at Cattle Point stating that the pass is required at those locations.
The $30 yearly pass can be purchased at Lime Kiln Park kiosk (limited hours).
The following sell the pass but charge a transaction fee: FH Hardware, King’s Marine.
Day passes can be purchased at the Park drop-box for $10
Here are a few links to help you figure out the new pass for Washington State lands.
Discover Pass
Recreation Pass Info WTA website
Federal Recreation Passes
Note: Federal lands and State lands each require a different pass.