Wolf, evasive, returning to back of butte (6)
I believe the answer is:
coyote
'wolf' is the definition.
(coyote is a kind of wolf)
'evasive returning to back of butte' is the wordplay.
'evasive' becomes 'coy' (I've seen this in another clue).
'returning' is a reversal indicator.
'back of' suggests the final letters.
The final letter of 'butte' is 'e'.
'to' backwards is 'ot'.
'coy'+'ot'+'e'='COYOTE'
(Other definitions for coyote that I've seen before include "Beast" , "Confines" , "Small North American wolf" , "Prairie-wolf" , "American prairie dog" .)