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 Skwala nymph still has a couple months left to go before hatching, but it's still a good representative of its species, which was extremely abundant in my sample for a stonefly of this size. It's obvious why the Yakima is known for its Skwala hatch.
This small stream flows into the White River near Mt. Ranier. It is rumored to have trout, although perhaps overfished. I fished it once without catching anything, but it was July 8th and the creek was still high and cold with snowmelt.