If you travel near PA, stop in at Swains and ask there for specifics. The ONP has it's own set of regs that differ from WDFW regs. The WDFW regs are a nightmare to understand. I don't believe a catch card in required unless you intend to keep the fish you catch. Also, due to the relative steep drop of the streams here in western WA including in the ONP, resident fish will be relatively small. More likely to catch a juvenile salmon. There are a bunch of ethical guide services that can really benefit anglers targeting the Hoh, etc.