The Little Mamie consists of a thin cavernous quartz vein along the footwall of a lamprophyre sheet. Ore mineralization is lean at surface, but intersections of as much as 60 centimetres of 30 per cent galena and sphalerite were obtained in drill core. The rocks are described as mica schist, micaceous quartzites and limestone of the Mississippian to Lower Permian Milford Group.

A shipment of 10 tonnes of ore was made in 1921 from which 17,107 grams of silver and 4989 kilograms of lead were recovered.