Posted this on a corn snake forum I belong to and several people think you found a red coachwhip.
Link 1
Scientific name: Masticophis flagellum piceus
Common name: Red Coachwhip or Red Racer
Size: 24.4-54.3 in (62-138 cm)
Distinguishing characters: A species with highly variable dorsal coloration; tan, grey, red, or pink with bold black or brown crossbars or blotches on neck which may blend together; venter pink; slender body and tail; large eyes with round pupils; often described as a red snake with a black head.
Juveniles: Black, brown or tan transverse bands on lighter background; black neck markings absent in hatchlings and faint in juveniles less than 24 in (61 cm) in length.
Additional notes: A fast moving diurnal snake that is difficult to capture. Bites, excretes musk and twists body when handled. Large individuals should be handled with caution.
Link 2 - more photos
One more link