Mineral almost exhausted in this state (6)
I believe the answer is:
oregon
'this state' is the definition.
(Oregon is an example)
'mineral almost exhausted' is the wordplay.
'mineral' becomes 'ore' (ore is a kind of mineral).
'almost' means to remove the last letter (almost the whole word is kept).
'exhausted' becomes 'egon' (I can't justify this - if you can you should believe this answer much more).
'ore' with its last letter taken off is 'or'.
'or'+'egon'='OREGON'
'in' is the link.
Can you help me to learn more?
(Other definitions for oregon that I've seen before include "Salem's state" , "West coast US state" , "area of the US" , "US state, capital Salem" , "W. coast US state" .)