Portland, Oregon area camping
In Oregon, there is no state law against simple nudity. In Washington there absolutely positively is. There is no federal law against nudity, but some agencies do restrict where and when it is permissible. HOWEVER!!! Some federal agencies have adopted state laws for certain lands, often depending on whether the federal reserve was established before or after the state was established. I strongly recommend checking with the local office for the particular agency as to the status on the land they manage.
BOTH, Washington and Oregon are open to nudity, not againest the law as long as it isn't lewd , we go campinig a lot in the northern part of Eastern WA. and yes it is Nude camping, however we are respectful of others while walking around others. our camp sites are well chosen but not hidden, We also drive nude on the back roads and some times on the highways in the convertible as well.
I like the Blue Mountains in Eastern Oregon and the Sawtooths in Idaho for my nude camping. It is remote enough that you can basically do what you want and you're on federal lands that don't have laws against nudity! Going in July and can't wait!!