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.
Unfortunately there's no good key to species of Cinygmula nymphs and I didn't find an adult, so this one will have to stay at genus level.
This mayfly was collected from the Dosewallips River in Washington on July 6th, 2020 and added to Troutnut.com by Troutnut on July 12th, 2020.