Mt Owen is situated between two regional thrust faults, the Hunter Thrust and the Hebden Thrust that limit the lateral extent of the coal seams. Seam dips vary throughout the deposit, with dips being steep (up to 45 º ) in the areas near the Hunter and Hebden Thrusts where parallel thrusts dislocate the seam by up to 40 metres.

Up to 22 mineable coal intervals are recognised, ranging in thickness from 0.2 metre to 10 metres, within a stratigraphic interval of approximately 350 metres, the coal seams comprise a total thickness of approximately 55 metres.

The seams for which there is potential for economic extraction at Mt Owen include the Lemington Seams, Pikes Gully Seams, Arties Seams, Upper Liddell Seams, Middle Liddell Seams, Lower Liddell Seams, Barrett Seams, Upper Hebden Seams and the Lower Hebden Seams.

Mining operations at Mt Owen Open Cut Coal Mine (MTO) began in 1993 under the management of Hunter Valley Coal Corporation Pty Limited (HVCC). Xstrata (now Glencore) acquired MTO in 2003. MTO was granted DA 14-01-2004 in December 2004, which was supported by the MTO Environmental Impact Statement (EIS), December 2003 (Umwelt, 2003).

A modification to DA 14-1-2004 was approved in December 2010. This allowed for the construction and operation of a rail facility on the MTO rail loop. Further modification was approved in 2014 to increase the CHPP to 17 Million tonnes per annum (Mtpa) run-of-mine (ROM) coal equivalent from MTO, Ravensworth East and Glendell.

In January 2018 an application was made to DP&E to surrender DA 14-01-2004 as it is replaced by SSD-5850. Approval to surrender DA 14-01-2004 was received from DP&E on 29 May 2018.

Mining at Mt Owen occurs within the Wittingham Coal Measures with the North Pit located between the Hunter Thrust and the Hebden Thrust. The North Pit currently extracts coal from 22 mineable intervals, representative of 11 identifiable coal seams. Coal seams present range from the Lemington to the Lower Hebden seam and range in thickness from approximately 0.1 m to 10 m.

A modification to DA SSD-5850 was approved in August 2017 to allow for the inclusion of the Greater Ravensworth Water Sharing Scheme (GRAWTS), and the construction of a water pipeline from Integra Underground Mine to MGO.

Mt Owen Continued Operation (MOCO) received approval in November 2016, under SSD-5850 (development consent/ project approval). The approval combined the existing development consents for Mt Owen and Ravensworth East, extending the operation until 2031.

A second modification to DA SSD-5850 was approved September 2019 to allow an increased disturbance area and extend mining operations to 31 December 2037. A third modification to SSD-5850 was approved January 2020 which was an administrative modification in which a land parcel was included within the Schedule of Land.

During January 2020, Modification 3 (Mod 3), an administrative mod, was approved by DPIE for the inclusion of one land parcel within the ‘Schedule of Land’.

Mining and dumping will continue in a south- easterly direction. Mt Owen has 38.5 hectares of rehabilitation planned, consisting of woodland areas.

MTO is operated by Thiess Proprietary Limited.

Mt Owen Open Cut Mine (MTO), including the MOC Coal Handling and Preparation Plant (CHPP).

The CHPP consists of a South ROM stockpile and North ROM stockpile of an approximate 350,000 tonne and 300,000 tonne capacity, respectively. ROM coal is passed through three stages of sizing using Abon sizers, and the sized coal is then conveyed to a 2,000 tonne surge bin that feeds the CHPP. ROM coal is crushed, sized, screened, separated and dewatered.

Mt Owen produces thermal and semi-soft coking coal for supply to the export markets. The thermal coal product is highly volatile with strong combustion characteristics and has been widely used for power generation.

Semi-soft coking coal produced by Mt Owen is used by steel mills for pulverised coal injection and as a component in the coke blend.