Species:

Drymarchon melanurus

Central American Indigo Snake

Some other names for this species:

Black-tailed Indigo Snake, Tropical Indigo Snake

Subspecies I've seen:
no photos
Central American Indigo Snake
D. m. melanurus
Subspecies:

Drymarchon melanurus melanurus

Central American Indigo Snake

April 11, 1998
Chaa Creek, Belize
I saw just the last third or so of this largish snake as it slithered away. The black tail made it very easy to identify, though.