Underground enthusiasts heading for certain states (6)

I believe the answer is:

cavers

I'm a little stuck... Click here to teach me more about this clue!

'underground enthusiasts' is the definition.
I don't know anything about this answer so I can't judge whether this works.

'heading for certain states' is the wordplay.
'heading for' indicates taking the first letters.
'states' becomes 'avers' (to aver is to declare or state).
The initial letter of 'certain' is 'c'.
'c'+'avers'='CAVERS'

Can you help me to learn more?

(Another definition for cavers that I've seen is " Potholers".)

I've seen this clue in The Independent.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.