If you are ultimately headed to ID, a side excursion in the ID direction puts you near
John Day Fossil Beds National Monument NP which is one of those "hidden" secrets in OR.
A great, but very small, RV park in nearby Dayville is
http://www.fishhouseinn.com/, They do take reservations and you would be wise to reserve. Just be prepared to not want to leave.
This is a very unique area for Oregon and I highly recommend trying to go through there. Make sure to plan enough time to spend a day at the Painted Hills Unit:
I love me some land yachting