Danger lurks in upper Illinois (5)

I believe the answer is:

peril

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'danger' is the definition.
(synonyms)

'in upper illinois' is the wordplay.
'in' indicates a hidden word.
'PERIL' is hidden in the letters of 'upper illinois'.

'lurks' is the link.
This may not be correct. It may belong to another bit of the clue.

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(Other definitions for peril that I've seen before include "Danger of serious kind" , "Immediate danger" , "Danger, hazard" , "Danger, jeopardy" , "risk" .)

I've seen this clue in The Globe and Mail.

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