The Windsor showing is located west of Bromley Glacier approximately 16 kilometres east of Stewart. The area was investigated initially in the early 1900s and has been sporadically explored up to 1974.
The area is underlain by argillite of the Middle Jurassic Salmon River Formation (Hazelton Group) intruded by a number of large diorite dikes. The argillite strikes approximately north and dips 40 degrees west.
The showing comprises crushed and silicified zones up to 6 metres wide which have approximately the same attitude as the host argillites. The main showing consists of 4.6 metres of quartz and silicified argillites mineralized with locally abundant pyrite, galena and sphalerite. Patches and lenses of galena and sphalerite contain high silver and low gold values. The main showing strikes 330 degrees and dips 40 degrees west. A number of smaller showings also occur in the vicinity.
The main zone has been investigated through several opencuts and a 23 metre crosscut tunnel. One cut yielded gold values of 18.2 grams per tonne across 1.5 metres (Minister of Mines Annual Report 1924, page 68).