Westside Mine is an open cut operation managed by mining contractor Hunter Valley Earthmoving and provides thermal coal for the Eraring Power Station. The Westside Mine is part of the Macquarie Coal Joint Venture, 80% owned by Oceanic Coal Australia Ltd (OCAL), a wholly owned subsidiary of Xstrata. The other Joint Venture participants are Marubeni Coal Pty Ltd (17%) and JFE Mineral (Australia) Pty Ltd (3%).

Mining commenced in 1992 and has subsequently had several owners prior to Xstrata, including FAI Mining, HIH Insurance, Glencore and Enex. Westside is approved to produce 1mtpa.