While I agree that this is a Scotoleon, it looks odd for C nigrilabris to me, and I don't think that the photo is sufficient to make a species level ID.

If the oddness is in terms of the abdomen, that would likely be because this is a male. Two of yours (and the vast majority of photos) are females. We have particularly few male records for the species (in fact, after annotating sex, we only have 4 other images of males on BugGuide to 32 images of females). Also, depending on the positioning of the abdomen, more or less yellow may show from underneath the tergies and sternites. As far as Scotoleon species, the vast majority don't occur this far north and, in our area, are more restricted to the south(west)ern states. In fact, the only other species reported this far north by Penny et al. (1997) is S. nivatensis, which is very different in the color of the pterostigmas, wing pigmentation, and a darker body (see tentative ID by Leon Tavares).

I was commenting on the pattern on the pronotum, which is very hard to assess in this photo, and generally important in the ID of Scotoleon. It is also well outside the stated range in BugGuide and well north of any other records in BugGuide or in iNat.

If S nigrilabris is known from WA (or adjacent areas) and other Scotoleon aren't, then I can't argue.

Stange (2004) directly places the species in Washington state. I still need to update a number of our ranges that were expanded as of that book but haven't had a good time to run through all of them yet. Looking at known records in the northwest corner of the range of the genus (BC to OR to WY TO MY), there are fairly sparse species records. Now, that being said, some species aren't very well studied, so range data isn't a definitive (take, for example, the population of Vella americana in Texas, readily distinguished by hindwing structure, not found in the literature and fairly well outside of the previously-known range). Here are the species with existing records there (bold entries noting records not in our currently-reported ranges):
• S. nigrilabris: ID, MT, WA, WY
• S. nivatensis: ID, OR
• S. peregrinus: BC, WY

Now, as far as patterning, that's generally less reliable than looking at male terminalia (though S. nigrilabris is rather consistent compared to some other widespread species). Using Stange (1970), the length of the terminalia, and what can be seen of its structure, seem to point strongly to this species as well (we could sort of consider 3 groupings of terminalia as long, short, and stubby*, where this would fall under short but seemingly not stubby). I arrive at couplet 3, where the yellow-color of both the pale body parts and the pterostigma single out S. nigrilabris. Come to think of it, I don't recall another Scotoleon with a yellow pterostigma, though Leon Tavares could say more definitively.

* "long" = at least 3/4 the length of the 8th abdominal segment; "short" being less than 1/2 the length of the 8th but 3x as long as wide; "stubby" being less than 1/2 the length of the 8th but no more than 2x as long as wide.

Thank you, i believe that is what it is. It looks like what is in my picture.

Brachynemurus abdominalis



Might be something close to that, at any rate. Maybe an expert will be able to say for sure.