Expanding Production and Reducing Costs at Golden Star's projects. Golden Star plans to expand production and reduce costs by developing two underground mines, Wassa Underground and Prestea Underground. This is expected to transform Golden Star's production and cost profiles, with production forecast to increase 60% between 2016 and 2019 while cash operating costs and AISC decline. Golden Star is on track to achieve its 2016 guidance and the underground development projects are advancing as planned, with infrastructure in place at Wassa Underground and stoping commenced in the third quarter.