The distance to the mountains (5)
I believe the answer is:
range
This clue is a double definition.
'the distance' is the first definition.
(I've seen this in another clue)
'the mountains' is the second definition.
(range of mountains)
'to' acts as a link.
(Other definitions for range that I've seen before include "Mountain stretch" , "Kitchen gadget" , "sight" , "Compass - scope" , "Old song: ''Home on the . . . . .''" .)