The Island of Death

Taken in a creek in Independence, Ky. I've seen big rock spiders. I've seen big wolf spiders. This thing was hangin out on an upraised part if a rock in a slow creek with small stagnant pools. He was eating one of those water roaches things when I took the pix, and then scared the buhjeezis out of me when my son moved a little too suddenly while I was perched over him, one leg hiked up the side of a rock ledge that is actually blue clay. When Berkeley jerked as he slipped on something closely where the spider splayed out, he JUMPED UP AND DOVE INTO THE WATER, then started it's way up the 'clay' ridge (really mf'n fast) almost up my striped Roller Derby socks, with me screaming around and almost spear-heading one of those stagnant pools where the water striders are skipping around all crazy and you know it smells like rotted leaves and rancidness at the bottom......
So can someone clarify him for me? He (or she!) was remarkably, beautifully marked and I was terrified and terribly excited to have gotten it's 3-inch span on digital and knew it while i could (or was running away and erratically screaming like a girl) when it streaked like a lightning bolt toward my Chucks.

Guess I've gone on enough. :p