Clue antelope crosses river in remote area (10)
I believe the answer is:
hinterland
'remote area' is the definition.
(I've seen this before)
'clue antelope crosses river' is the wordplay.
'clue' becomes 'hint' (synonyms).
'antelope' becomes 'eland' (eland is a kind of antelope).
'crosses' is an insertion indicator.
'river' becomes 'r' (abbreviation for river).
'eland' placed around 'r' is 'erland'.
'hint'+'erland'='HINTERLAND'
'in' is the link.
(Other definitions for hinterland that I've seen before include "area around a port" , "Remote area of a country" , "Remote inland areas" , "remote country region" , "Remote areas of a country" .)