Open pit operations at Mt Morgans are sourced from the Jupiter mine area located adjacent to the site’s treatment plant. Jupiter is approximately 15km east-south-east of Westralia.

Jupiter lies within the Jupiter Corridor which is defined as a 2km long north-south trend containing three main syenite intrusive bodies, which from south to north, are termed Ganymede, Heffernans and Doublejay. Several smaller syenite dykes and intrusive bodies are found proximal to the three main syenites, and all are contained within the Jupiter Corridor.

Approximately 150,000 ounces of gold was produced from Jupiter Open Pit during the period 1994-1996. Post the completion of mining activities in 1996, the remnant resources remaining at Jupiter were 800,000t at 2.8 g/t for 73,000 ounces (above a 1.5 g/t lower cut-off grade). All remaining resources were situated below the base of what is now termed the Doublejay pits. 

Mining operations at Jupiter contributes the primary ore feed to the treatment plant which combined with additional ore sources including ROM stockpiles, contributes to the total ore feed for the Mt Morgans Plant.