This one was surprisingly straightforward to identify. The lack of a sclerite at the base of the lateral hump narrows the field quite a bit, and the other options followed fairly obvious characteristics to Clostoeca, which only has one species, Clostoeca disjuncta.
Trnnflt on Jan 1, 2017January 1st, 2017, 10:58 pm EST
Saw this brown mayfly on my door the august morning i arrived in jackson hole at the Elk Refuge Hotel cross the road from flat creek in Jackson Hole.
I'm new to learning about these aquatic insects and wondered what this one is?
Taxon on Jan 2, 2017January 2nd, 2017, 3:31 am EST
Hi Michael-
I believe your avatar image to be that of a male subimago (dun) of genus Callibaetis, which is also known by the common name of Speckledwinged Dun, among numerous others.