Raging rapids of the Columbia River

We readers usually think of dams as being a way to store water & release it for irrigation. This is true, of course, but the dams on the Columbia River also restrained the river from flooding or smoothed the paths of boats. The 1243-mile Columbia was a killer river in many places. The shores narrow to force the river to run through restricted spaces, creating powerful currents and rapids. The river had an average descent of about two inches per mile. This may not seem like much but in restricted areas, it sort of "piles up" and rages through. In Canada at its northwesterly hairpin turn from northwesterly to south-southeasterly, the river ran immediately through a wicked canyon so dangerous that early canoeists "lined" their canoes through. That is a system where the handlers use ropes on both sides of a river to steady a boat/canoe through rough water, while they are walking along its shores as best they can. That canyon was a challenge even to walk through. Mica Dam smoothed out that hazard. The stunning Columbia Ice Fields contribute to the Columbia River waters now monitored by the dam, and three other significant rivers or streams join forces at the junction, too. I would like to have seen the roiling and raging Columbia before that dam.
Did you know that the Columbia dams in BC, Canada, were not particularly needed at the outset for creating power? Canada made a treaty with the USA  to create the power but store it to be released as needed. I never really understood how one can store power that already has been created, do you?? Anyway, the worse need for the Canadian dams and the USA dams was to control flooding. Parts of Portland and other cities downstream were flooded during some melt-offs to the  point of needing boats to get around town. It is interesting to read the accounts of residents along the river who had to cope with such disasters.