W. Mountain Gomphid?

I think this is a Western Mountain Gomphid, Ophiogomphus bison and welcome confirmation or correction to this ID. This was taken in July, 2008 and I have hoped to get a better photo of one of these since, but another summer has past and I have not even seen another let alone gotten a better shot.

My guide says these range only California and Nevada but as we are about 100 miles north of California it is easily possible that this is the ID. Guide states that these settle only briefly on rocks and low vegitation and are only active on sunny days. Perhaps this is the only shot I'll get, so I have processed what I felt was not the best of images. It has been sharpened significantly, noise reduced also significantly and processed with Olympus Studio 2 and Color Efex pro.

Please be critical about anything you feel should have or can be improved.

Olympus E-510.
70-300mm F4 lens
FL 300
1/320 sec @ F6.3
0.0 EV
ISO 100
manual focus
monopod
Cropped about 10% from FF only to the right side.

Large view provided