The Underground mine workings are located to the south of the New England Highway. Access is from the northern side of the New England Highway via portals in the southern highwall of the Arties Pit. The main headings are generally aligned beneath and adjacent the New England Highway corridor, thereby minimising the impact of subsidence whilst maximising the recoverable area to the south. The underground mine is a multiseam operation mining the Pikes Gully, Upper Liddell, Upper Lower Liddell and the Lower Barrett seams of the Foybrook formation. Coal is mined via longwall extraction methods. The underground operates 24 hours per day, 7 days per week. The underground mine extracts approximately 3.2Mtpa of ROM coal.

Subsidence Management Plan (SMP) approval has been received for Longwall Panels 1 to 4 in the Pikes Gully seam and first workings approval has been received for Longwall Panels 5 to 9. Extraction of the second seam, Upper Liddell is expected to commence in 2011.