According to the official webpage, registration for the Washington State Star Party 2025 will open on May 1, 2025.
From their "Rules and Regulations" webpage:
Official operations start at 9 A.M. on Tuesday, July 22nd [2025]....The event officially ends on Sunday, July 27th [2025].
Discover Pass is REQUIRED
A Washington Discover Pass is required to attend the event due to the property being under the administration of the Washington Department of Fish & Wildlife (WaDFW). Your registration does NOT remove the requirement that you have a Discover Pass for your vehicle(s). We will NOT be able to issue Discover Passes onsite nor does WaDFW offer any capacity to issue onsite Discover Passes. An annual Discover Pass can be purchased through the Discover Pass website for $35, good for one year from the date of issue, or you can purchase one when you renew your vehicle registration with the Department of Licensing. There are also certain Washington fishing and hunting licenses that grant Discover Pass privileges, please check if this applies if you hold one of those licenses.
That WaDFW webpage says:
Vehicle Access Pass for license holders
A Discover Pass is not always needed to access WDFW-managed lands. A Vehicle Access Pass is issued at no charge by WDFW with the purchase of any annual hunting, trapping, or fishing license, excluding an annual razor clam or shellfish/seaweed license. A Vehicle Access Pass allows you to park at WDFW wildlife and water access areas. A Vehicle Access Pass is transferable between two vehicles.