The way points of this bicycle route:
A challenging day ride for a nice over-nighter on the Columbia River.
At this point you can take the single track/fire road on the east side of the creek or you can cross over and take the bumpy dirt road on the west side.
There's a ped bridge here (Sandifur Bridge). I promise!
Hop on the Centennial Trail here.
(still on Centennial Trail -- Google Maps doesn't show the trail-- guessing on exact location)