Line of mountains (5)
'line of mountains' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for range that I've seen before include "Roam" , "Take sides" , "Cut; cultivated plant" , "Open grazing land or cooking stove" , "Aga or mountain, perhaps?" .)
(Other definitions for chain that I've seen before include "Set of links" , "a number of hotels" , "Series of connected things" , "series of shops" , "number of shops" .)