My folks lived in Northern WI between Washburn and Bayfield. The "Green Bay Bugs" would come off so thick at times they'd have to scrape the bridges with a grader to clean them off. One time in the peak of a heavy hatch we drove into Washburn to hit a few local establishments. As we drove into town it looked like the town was gone. They were so thick they covered every window and lighted sign so hardly any light was getting thru. There were actual piles under the street lights that had to be shoveled up the next morning. National news mentioned great fishing during the hatch. Not so. The hatch could be so heavy you couldn't raise a fish thru the bug covered surface for anything. Even the fish we caught in Superior were full of the flies but still tried to eat a flutter spoon.