I'm not there (sigh) so I don't know fo-sho if the timing is right, but last year we tore them up about this time on the Piledriver. Take a canoe to the confluence of Piledriver and Moose Creek. They'll be against the far shore in the clearer Piledriver water, finning into the murk from Moose Creek. I distinctly remember standing on an ice shelf and catching the heck out of them. They'll be there for a bit (week or two?) before they disperse up Piledriver for the summer. If you time it right, it's pretty ridiculous...and a fun first outing! Copper Johns won the day last year...wish I was there - tight lines!
Attached is a fish called an Asp I believe...even in Iraq I gotta get my fish-on between missions...lol