The Common Whitetail or Long-tailed Skimmer (Plathemis lydia) is a common dragonfly across much of North America (Wikipedia). Only the males have this white body. The females have a brown body and a different wing pattern. This dragonfly hawks for mosquitoes and other small flying insects. They often return to the same perch, like this spot on a rock, which makes getting a shot quite predictable and not so difficult.
I was hoping to point my lens actually at some birds along the Mississippi between Harpers Ferry and Lansing, Iowa, when this opportunity for a shot came up. Not enough time to go back to the car and change lenses, so I just stepped a few feet back and used the Sigma 150-600 for this photo. I can’t rave enough how pleased I am how this lens performs, even handheld.