Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
This was one of many of its species which were gathered in small, low-flying swarms of about a dozen insects near the alder trees in the afternoon on a small stream.
This is a naturally crippled female Isonychia bicolor dun. One of her main wings came out as a deformed, crumpled yellow object. I found her flopped over on her side struggling on the surface of a small stream.