X2 on what keithu said about riding east of Prineville. Take 26 east towards John Day, left on 395 at Mt. Vernon, north to Long Creek, then west on 402 to Hamilton, Monument and Kimberly. Take 19/207 to Spray and Service Creek, then north to Fossil. Then 218 to Clarno, Antelope and Shaniko. Grandma's Ice Cream shop next to the Shaniko Hotel is worth the stop if it's still open. She was the one who lined me up on taking 218 to Antelope and Fossil. The Oregon Hiway crew had just finished paving the road over to Fossil. New tarmac, no traffic -- it was heaven. This was many years ago. The last time I went through that area it was on fire. The road was fine, just couldn't see anything because of the smoke.
Have fun!!!