"Paddlec1" wrote in message
...
It might be worth noting that the high water on the Columbia would not
necessarily have started with the coming of spring. Although the lower
elevations that feed the river would run off sooner, snowmelt in the
higher
areas would not peak much before June, if that early. Lewis and Clark had
time
for a spring run up the river.

Since the source of the Columbia is in the Canadian Rockies, where I paddle
(I've never actually paddled the Columbia, but I have paddled several of its
tributaries), I can feel confident in saying that while it varies depending
on location, peak flow tends to be late in June.

-Paul

I agree. I live very close to the headwaters of the Snake River which feeds the
Columbia, and May can look like Janurary up here. Since the Columbia basin in
what is now Washington State is desert and has very little if any runoff, my
hunch is that anyone traveleing upriver predams would have had a wide window of
opportunity through spring, and maybe even into early summer.

Dennis