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 is a subspecies M. terminatum terminatum, formerly called Stenonema. Found mostly in larger rivers in western Montana. This is an immature nymph.
This mayfly was collected from the Flathead River-lower in Montana on November 23rd, 2005 and added to Troutnut.com by Bnewell on June 26th, 2011.