Hexes will live anywhere there is silt and sand. I've seen hexes up from the lake on the lower Clinch in july I think. Don't quote me on the month. Where I'm from in Loudon we had awesome hatches of "Willow Flies " either in late June or into July. Wasn't until much later I learned they were Hexagena Limbata. An un-weighted size 8 3xl tellico or haresear works great.