Anax junius

The above is the female. This is the male.

"The face is pale green, with a distinct black spot on the top of the frons ... The thorax is green, with brown represented only lightly on the lateral sutures. The wings are clear, the costa yellow. The abdomen is mostly blue, with green on segment 1 in males, and greenish brown or reddish brown throughout in females."

"Thorax bright green, with black dorsal stripe that broadens rearward. Eyes olive green with a bull's-eye pattern on forehead. Wings clear with yellowish to brown stigmas" (Blair Nikula & Jackie Stokes. 2002. Beginning Guide to Dragonflies. New York: Little Brown and Company. P. 80)

This is BugGuide's Common Green Darner