Unfortunately the Federal discount passes are not accepted by the Oregon State Parks. However, whatever Oregon State Parks campground you stay in will be well worth the fee. I've camped in most of them and they don't disappoint.

I don't think so. The pass works for National Parks, Monuments, and Reserves, etc, but not for State Parks.

No. It is an Oregon State park, not a federal park.

No it does not.

I don't believe so. https://stateparks.oregon.gov/index.cfm?do=visit.day-use