I believe that this is Hogna helluo, although I am by no means a spider expert. I found her while I was out trying to shoot some Acris this evening … which didn’t really work out as well as I hoped, but as long as I get something good out of it, I’m not complaining.
Edit: This is indeed H. helluo, at least according to my highly knowledgeable office mate whose dissertation work is on these spiders.
Tamron 90mm f/2.8 Di Macro Lens on a Canon T1i Rebel
ISO 100 at f/16, 1/100 sec
Diffuse flash in whitebox
Image editing in Adobe Photoshop CS5