"Wolfgang" wrote in message news:...
Hexagenia limbata sounds like a better bet to me. I've never seen them
that thick myself, but there are persistent stories of hatches so heavy
that snowplows or fire hoses are required to remove them from roads.
Backwaters on the Mississippi River provide plenty of ideal habitat (the
nymphs burrow in silt), the time of year is right, and the time of day is
right.

Wolfgang

I was up at Maumee Bay several years back, the hatch was so thick it would
stop traffic due to the fact that if you tried to drive through a cloud of
Hex it would smear the windshield instantly.
It was truly amazing. I had never seen anything like it. EVERYTHING was
covered. You could not take a step without crushing 8-9 per step. The trees
took on a new color from being covered, buildings, EVERYTHING. At first it
was neat, then annoying as you were constantly covered in bugs, but it got
to the point that as long as they stayed out of your mouth and off your eyes
you didn't even bother to pick them off of you anymore. I loved it. From
what I heard at the campground you couldn't catch a fish to save your life,
this being understandable, those fish surely had themselves stuffed to the
gills by day 2 of the hatch. For a couple years after I was still
occasionally finding dead mayflies in the camper. I will never forget it.