Common Whitetail, Libellula lydia (Plathemis lydia in some sources).
In mid-summer, when birds are quiet, one's attention turns to odonates (dragonflies and damselflies). One of the most conspicuous is the pruinescent male of the Common Whitetail.
Pruinescence is what makes them white (or blue or red in other species).
The Common Whitetail is also among the most cooperative, typically perching within easy camera range, often on the ground. (In this case, on the bleached wood of a split-rail fence).