Dan,
You are correct on your assessment on there not being much fall color in the Central Oregon area. There are some beautiful patches, but not widespread. The skies are usually dark and clear though.
More color on the western side of the Cascades, but then you will have clouds.
I would think just south of the Tahoe area might offer some good opportunities.
Western weather patterns are about to change so the smoke situation might improve for you soon.
If you do drift as far as Central Oregon, let us know.
Steve
