The take on it here in PA is that it more or less mimics state laws. For us, we just got carry in state parks in the last legislative session, but the wording is ambiguous. CC for licensed carriers is clearly in state parks in PA as of December 17th IIRC, but OC is unclear and may be interpreted not to be. If OC isn't allowed in state parks then it wouldn't be in national parks. We are trying to sort that out.
What is your situation with state parks in WA? And rememeber this only covers the park. Federally owned buildings are still a no no (for example Independence Hall in Philadelphia is ironically off limits)
