Ravine identified by Tory touring a US state (6)
I believe the answer is:
canyon
'ravine' is the definition.
(I know that ravine can be written as canyon)
'tory touring a us state' is the wordplay.
'tory' becomes 'con' (abbreviation for conservative).
'touring' means one lot of letters goes inside another (touring can mean going round).
'us state' becomes 'NY' (abbreviation for New York).
'a'+'ny'='any'
'con' going around 'any' is 'CANYON'.
'identified by' is the link.
(Other definitions for canyon that I've seen before include "(N. Am.) ravine" , "'Deep ravine, gorge (6)'" , "Deep fissure" , "Narrow steep-sided valley" , "deep container for water" .)