Pole put up, fixed in English county (6)
I believe the answer is:
dorset
'english county' is the definition.
(I've seen this before)
'pole put up fixed' is the wordplay.
'pole' becomes 'rod' ('rod' can be a synonym of 'pole').
'put up' is a reversal indicator.
'fixed' becomes 'set' ('set' can be a synonym of 'fixed').
'rod' back-to-front is 'dor'.
'dor'+'set'='DORSET'
'in' is the link.
(Other definitions for dorset that I've seen before include "South coast county" , "County of south-west England" , "part of England" , "Weymouth's county" , "South-west area" .)