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.
Steamntrout on Jun 14, 2017June 14th, 2017, 8:38 am EDT
Looking at Purdue's May Fly Central it shows nebulosa being found in Canada's Far North, North East and North West as well as USA's North East, South East & Far West.