Man from East London circumventing old Ohio ravine (6)
I believe the answer is:
arroyo
'ravine' is the definition.
(type of ravine or gully)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for arroyo that I've seen before include "Rocky ravine" , "Dry river gully" , "dry course" , "Dry gully; yo roar (anag.)" , "Often dry desert ravine" .)