Argia tibialis (Blue-tipped Dancer) ♀.
Size: approx. 35 mm. Photo: 05/08/16, noon.

The females in this species occur in blue and brown forms, but both have wide black shoulder stripes. The abdomen of these dancers is all black with very thin pale rings. The species occurs in thirty US states and is typically found at small, wooded, sandy streams or ponds and less often at larger rivers. I discovered this brown form perching on our deck.  
bug guide (this photo):
Giff Beaton: