The gold recovery must have been huge, they put a lot of effort and investment into those dredges.
Indeed!
Some of the original claims were mind-bogglingly rich, to the point where much of the Klondike is now still being profitably mined for the third and fourth times, essentially going through much of the same dirt! I didn't have much trouble finding a little bit of gold, and that with just a few pan samples!
As seen in this other thread, here:
https://www.officeofsteamforum.com/off-topic/fifteen-years-ago-today/