Southwestern tribe with a snake dance (4)
I believe the answer is:
hopi
'southwestern tribe with a snake dance' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for hopi that I've seen before include "Arizonan Pueblo Indian" , "Arizona inhabitant" , "Native Americans" , "Member of a Pueblo Indian people of northeastern Arizona" , "North American Indian people" .)