The tower has something to do with navigation, and I could not tell you what that is. If you know, please leave a comment or send e-mail!
I forgot to take a close-up of the sign, so I enlarged the small one and tweaked the levels. It says:
U.S. Government Property
Report Violations to:
U.S. Army Corps
Interestingly, on the board to the left of the sign, someone who could almost spell wrote graffiti that says, "Astoria Rescue Mision." Perhaps it's a note to the needy that help is on the other side of the bridge.
This blog is sponsored by Tapir and Friends Animal Store.