Hint: the Portage we just finished is over 2,500 m
Gibson L to the Nip? I haven't been there (yet), just deducing from your clues at this point...
Definitely the right 'quadrant' of the park - but not there. It is a river tho (not a creek or obscure shot of a lake)
South River? end of the P2770?
Evan Briden wrote:South River? end of the P2770?
Bingo!