The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
This one was surprisingly straightforward to identify. The lack of a sclerite at the base of the lateral hump narrows the field quite a bit, and the other options followed fairly obvious characteristics to Clostoeca, which only has one species, Clostoeca disjuncta.
This stonefly is one that is fairly common in higher altitude lakes, especially in western North America. I have collected it in higher lakes in Glacier National Park, Montana. Dick Baumann tells me that in a recent publication this stonefly has been renamed Skwala compacta.
When checking out Skwala compacta, I noticed that the Valid Stonefly Names for North America list maintained by Ed DeWalt has not been updated since 3/19/2009. Do you have any insight into why that might be?