The Whistler showing is located at the headwaters of Bobbie Burns Creek in International Basin. The area is approximately 32 kilometers southwest of Golden.

The occurrence is located in the Purcell Mountains. The area is underlain by northwest trending metasediments of the Upper Proterozoic Horsethief Creek Group. Regionally, this group consists of slates, argillites, quartz-pebble conglomerates, grits and minor limestone.

The formations in International Basin, as well as the adjoining main valley, are folded and fractured across the bedding. Rock types include greenish grey schists, dark slaty schists (in which cubes of pyrite are a characteristic feature), quartzites, slates and conglomerates. In the bluffs and ridges the formations have been folded to form a large anticline. Cutting the metasediments are a series of well-defined quartz veins trending north and south. These are intersected by another series of quartz veins trending about 300 degrees.

At the Whistler occurrence an opencut of three metres is started in a large quartz vein. The strike of the quartz vein is 305 degrees. The vein is barren where exposed. There is a second opencut on one of the cross cutting veins showing a small quantity of iron and galena. The vein may be traced on the surface for 30 metres.