The Mavis (Lot 2877) is located at an elevation of 1125 metres, east of Greenwood and immediately south of the Bay Fr. (Lot 3285; MINFILE 082ESE005) occurrence.

The area is underlain by chert, siliceous argillite and siliclastic rocks of the Devonian to Permian Knob Hill Group and undivided sedimentary rocks of the Carboniferous to Permian Attwood Group, which have been intruded by a granodiorite of the Jurassic-Cretaceous Greenwood stock, later referred to as the Cretaceous Anstey pluton. To the south, ultramafic rocks of the Carboniferous to Permian Mount Roberts Formation outcrop.

Locally, the Mavis-Bay-Tiptop occurrence quartz vein has been traced south on the Mavis (L.2877) and Tip Top (L.1229) Crown grants. The vein consists of braided quartz-carbonate veinlets enveloping lenses of mineralized country rock hosting pyrite, galena, sphalerite, chalcopyrite, petzite and free gold. A full description of the vein can be found in the Bay (MINFILE 082ESE005) occurrence.

Another zone of mineralization on the Mavis (L.2877) Crown grant, located a short distance to the south near the power lines, consists of a garnetized limestone (skarn?) hosting magnetite and chalcopyrite. In 1963, a sample of skarn mineralization yielded 0.77 per cent copper, 1.60 per cent zinc and 29.1 grams per tonne silver (Property File - G. Addis [1963-07-12]: Letters and Reports on the Bay Fraction and Adjoining Claims).

On the Tip Top (L.1229) Crown grant a tunnel, driven 120 metres south of the shaft on the Bay-Mavis vein, is reported to be developed on outcrop-altered (skarn) rocks overlaying a diorite contact hosting chalcopyrite and pyrrhotite.

In 1906, a 3-metre drift was run from a point 10 metres down in the shaft. From 29 tonnes of ore, 591 grams of gold and 1742 grams of silver were produced. In 1908, the Bay (MINFILE 082ESE005) and Mavis claims were combined as the Tiptop claim and operated by Tiptop Mining Co. through 1920. Another shaft and tunnel are reported on the Tip Top (L.1229) Crown grant.

In 1940 and 1963, the area was examined and sampled by The Granby Mining Co. Ltd.

During 2008 through 2012, Grizzly Discoveries Inc. completed programs of soil, stream sediment and rock sampling, geological mapping and ground geophysical surveys on the area as the Overlander area of the Greenwood property. In 2011, two samples (11CAP057 and 11CAP210) from the area yielded values of up to 22.50 grams per tonne gold, 492.0 grams per tonne silver, 2.01 per cent lead and 0.31 per cent zinc (Dufresne, M. (2013-11-25): Technical Report for the Greenwood Gold Project).