That hatch was Chironomids. I've seen it 5 times as heavy as it been this year. It is incredible. I'm pretty sure I ate a couple the last time I was there carrying my tube down to the water..
Chironomid is another word for Midge - one and the same.
Yeah, seen some epic ones out there too, 6 inch thick mats of shucks along the shoreline, and every blade of grass just covered with them.
Glad you had a great day out there !