We came across these on the top portions of submerged rocks in the Dayton area on the Touchet this morning. This one is small at 3/4", some were up to 1 3/4" I think. Had 6? dark legs to hold on to rocks in the semi-swift water. They were everywhere. The lower sides and undersides of the rocks had the brown cone type, 1/2" with green worms, which I think are the Brachycentridae, (Grannom), but I couldn't ID these big guys. Should have taken one apart but at least I know what to imitate outside. Thx, just always curious about this stuff. Gold ribbed hares ear did fine, even though I didn't have any big enough. Some were 6 3xl long I bet.