Midway down Five Mile Rapids on the Petawawa

Rolling Dam?

Nipissing River, below the 230m portage and upstream of the 945m (915m).  That is, between the first and second portage upstream of Cedar Lake.

One last try:  bottom of the portage around High Falls.

I guess I just have to keep working upstream until I get to Big Bob Lake and then give up in frustration.  I further suspect that Martin is just about to pounce.

On that basis, I guess it must be from the campsite at the foot of the portage around Gauthiers Dam -- "Nipissing River -- Osler Marsh" according to Jeffrey.  But I have to admit, I have no mental picture of that location at all (it's been over 30 years since I was there).

Thanks Shawn.  It's always nice to get one, but with four guesses and a lot of clues, I don't think I can claim much in the way of bragging points.  Anyway, I'll post something a little later -- providing our power doesn't go out.