Length 7-8 cm
Caught in stream bed (gravel)
Same animal as photos from jameyred, http://www.inaturalist.org/observations/3248013
There are additional photos of this same animal. I have some more that are not as well-lit or focused, but might have other distinguishing characteristics visible.
Long-Tailed Salamander (Eurycea longicauda) from Tishomingo, Mississippi
Cave Salamander (Eurycea lucifuga) from Tishomingo, Mississippi