Last of troops drank up supplies found here (6)
I believe the answer is:
depots
'supplies found here' is the definition.
(a depot might store supplies)
'last of troops drank up' is the wordplay.
'last of' indicates one should take the final letters.
'drank' becomes 'toped' ('tope' can be a synonym of 'drink').
'up' says the letters should be written backwards (in down clue: letters go upwards).
The final letter of 'troops' is 's'.
's'+'toped'='stoped'
'stoped' reversed gives 'DEPOTS'.
(Other definitions for depots that I've seen before include "HQs" , "Stations where passengers or goods are unloaded" , "Storage places" .)