Sheep herder originally re-dug yonder pit (8)
I believe the answer is:
colliery
'pit' is the definition.
(I know that pit can be written as colliery)
'sheep herder originally re-dug yonder' is the wordplay.
'sheep herder' becomes 'collie' (collies are sheepdogs).
'originally' indicates taking the first letters.
'dug yonder' becomes 'y' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
The first letter of 're' is 'r'.
'collie'+'r'+'y'='COLLIERY'
Can you help me to learn more?
(Other definitions for colliery that I've seen before include "Pit" , "Where a coalminer goes to work" , "Coal mine" , "Coalmine and surrounding buildings" , "Mining complex" .)