This specimen resembled several others of around the same size and perhaps the same species, which were pretty common in my February sample from the upper Yakima. Unfortunately, I misplaced the specimen before I could get it under a microscope for a definitive ID.
This specimen was the first record from Montana and the first record from the mountain west except Alberta where it was first described. It was found in temporary ponds.The nymph has double gills on all segments. The abdominal stripe is an important feature for identification