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.
I'm not sure if this cranefly larva is in the genus Hexatoma or Limnophila, but the habitat suggests Hexatoma. Its coloring is iridescent, and I've never heard of that before. However, there is an insect virus genus Iridovirus which can infect craneflies and causes iridescence. It has not been reported in this region as far as I can tell, but perhaps it is the culprit. It makes for beautiful pictures.