Variegated Meadowhawk (Sympetrum corruptum) photographed in the Bodega Dunes on 16 August 2012. Total length (head to tail) is ~4 cm.
Note the complex color pattern on the abdomen (red, orange, white, gray, brown, and black). You can also see red and yellow venation at the leading edge of all four wings.
From the side, look for two white and yellow stripes on the brown thorax. In the image below, they're hidden but still visible behind the wings.
The eyes are large — in dragonflies, they take up the majority of the head. They're red-brown above, and gray with dark spots below (see photo above). The "face" is metallic copper (next photo).
Variegated Meadowhawks are unusual within their genus for long-distance movements along the coast in the fall.