I'd Say upper Cedar river about 20 years ago. How did you get your boat in there? Must have had some help from high places.
How do I know for sure? ...one great memory and good analyst skills.

Edit, to further answer your question, the section is within the upper watershed, cant tell exactly where. would guess you either ran from the Fort Titon area down to the lake, or from Cedar falls area down to Bagley Junction area. I will tell you exactly how I came to my conclusion once the contest is over.