can you just walk in

You can just walk in but still need to buy a day pass or discover pass to park a car n its good for day use in all State parks. Little side note, if your on ssi or disabled your pass is free if you apply on line

You need to have or get a discovery pass.

Theres rarely anyone at the ranger station at Lewis and Clark. You can walk in , but if your going to park your car on state property you will need the discover pass.

Yes you can just walk or drive in. But to stay you need to pay to camp and you need a discovery pass to visit all parks in Washington state.

I'm tired

I am not sure because we always have a park pass. Stop at ranger station and talk to them