Northwest Forest Pass
The Northwest Forest Pass is required at any US Forest Service Trailhead in Washington and Oregon that charges a day use fee. You'll need a Pass for each vehicle you bring to the Trailhead. For avid hikers, the Annual Pass is ideal, however if you only plan to take a few outings a year to USFS Trailheads, pickup a Day Pass. For more complete information on the Northwest Forest Pass, check out the USFS website.
The Discover Pass is required at some Washington State Parks, Department of Natural Resources lands, and Department of Fish and Wildlife trailheads. In all, the Discover Pass helps maintain close to three million acres of state-managed lands in Washington. For more information, check the Discover Pass website.
National Park Pass
In Washington, the National Park Pass is used in only Mount Rainier or Olympic National Park. Passes can be purchased at the park entrances and are good for seven days. For more information check the websites for the Olympics or Mt. Rainer.