Washington State Parks offers several "free days" when a Discover Pass is not required to visit a state park.
According to the National Environmental Education Foundation website, "National Public Lands Day is the largest single-day volunteer effort for America’s public lands."
"Each year, hundreds of thousands of volunteers come together on the fourth Saturday in September to assist with various projects designed to restore and enhance public parks, forests, waterways and more. From trail maintenance to tree planting—volunteers of all ages and abilities roll up their sleeves and work side-by-side to care for public lands. The day also features a variety of hikes, bike rides, community festivals, paddling excursions, and other fun outdoor activities—all set on the backdrop of the country’s public lands and waterways."
Please note, free days apply only to day use (not overnight stays or rented facilities). A Discover Pass is still required to access lands managed by the Washington state departments of Natural Resources and Fish & Wildlife on these days.
Sno-Park permits are still required on free days at designated Sno-Parks during the winter season.
The Discover Pass is a $30 annual or $10 one-day permit. Support state parks by purchasing your annual Discover Pass, and enjoy a whole year of outdoor fun on Washington’s beautiful state-managed recreation lands.