Vail trail (3,3)
I believe the answer is:
ski run
'vail trail' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ski run that I've seen before include "Boggy, swampy" , "A trail for winter sportsmen" , "Recreational snow slope" , "Downhill course in winter" , "Snow-covered slope" .)