I believe this is a bar-winged skimmer or a great blue skimmer, or maybe a blue dasher but I’m not sure.  I submitted an ID request to an excellent resource: BugGuide.net. Will post correct ID once I get it. Anyway it’s been awhile since I posted a dragonfly picture, so here you go.

update: it’s a great blue skimmer (Libellula vibrans)