This individual--like the several others seen today--was perched at ground level (on bare ground or patches of dead grass from previous mowings) between clumps of mowed bunchgrass on the mowed walking paths. All chose this kind of perch--at the margin of the lower level, under partial cover of the mowed grass (which is mowed about 4-5 inches high on these trails across open grassland.)

When approached, it flew low and zig-zag about 5-7 yards, then found another place to perch. It was skittish and difficult to approach; this individual was the only one that let me get close enough for a half-decent shot. The bright yellow terminal segments of the abdomen and bright blue eyes helped in spotting it when it landed; the other markings blended well with dead/dry grass, as did the legs, so I could not get a focus on them through the wings.

This is my first sighting of a clubtail-type dragonfly, and while I can rule out a lot of possibilities (by range or appearance) I still am not sure what it is. It was not possible to get a frontal or complete dorsal view (uncooperative dragon!) but I have some shots (blurrier) showing that the dark "rings" are complete across the top of the abdominal segments, and it clearly has the male secondary genitalia. I'm guessing it's a flag-tailed spinyleg (that's the closest match I can see) but since I note from the images here that other people have made wrong guesses on that particular species, I could be wrong too.