Poison-oak can turn red in autumn, but this image is from the middle of summer .
Autumn Poison-oak with pink leaves vining up a an Oak / Quercus. The Oak is green.
Summer Poison oak in the shade with fairly large leaves.
Summer Poison oak with glossy green leaves in the Columbia River Gorge.
Cluster of Poison oak berries. Sort of a berrylike-capsule.
Leaf about 80 feet from its 100' tall vine up a redwood. Beware of picking up pretty leaves.
Poison oak vines grow to 4" in diameter. Saw one on Hiouchi redwood trail 180 feet tall.
You won't see this on shrubby ones in the field. This is how Poison oak fastens to trunks.
Poison-oak also turns yellow / yellow-green. The next redwood a red leaves vine.
Enlarged, I counted about 78 rings or years. This was cut near a redwood trail repair.