MtMan-List: direction again

[Rkleinx2@aol.com]

Hello the List
I'm getting mixed answers to my prior question.  What caused me to ask was
this line from Dale Morgan's  1953 book 'Jedediah Smith' in which Morgan
states....
"The Hudson's Bay Company's advance base, Flathead Post, was situated on the
right bank of Clark's Fork at present Eddy".
I can't find Eddy on a map but it's beside the point.
So the question remains.... when one writes /says that something is on a
particular side of a river, is he looking upstream or downstream?    (I've
always assumed upstream but something has made me doubt).
'Thank you' to all who took the time to reply previously.
      Dick