A few ready to follow river to county (8)
I believe the answer is:
somerset
'to county' is the definition.
(English county)
'a few ready to follow river' is the wordplay.
'a few' becomes 'some' (both can mean a small amount of something).
'ready to' becomes 'set' (synonyms).
'follow' is a charade indicator (letters next to each other).
'river' becomes 'r' (abbreviation for river).
'set' put after 'r' is 'rset'.
'some'+'rset'='SOMERSET'
(Other definitions for somerset that I've seen before include "Old English county" , "SW county" , "Maugham" , "English territory" , "County; acrobat move" .)