The Theda Bara showing is located about 9.5 kilometres due south of Alice Arm near the headwaters of Roundy Creek. The area was investigated for base and precious metals during the 1920s and again during the 1960s.

The region is underlain by Eocene Coast Plutonic Complex rocks intruding Middle Jurassic to Upper Cretaceous Bowser Lake Group argillite, shale, siltstone, greywacke and conglomerate. The sediments have been folded and altered to biotite hornfels.

The showing consists of north-northeast striking quartz veins, less than 0.3 to 1.2 metres wide, in a shear zone. The zone strikes 006 degrees, dips 80 degrees west and is developed in argillite intruded by granodioritic and lamprophyre dikes. The veins contain variable amounts of pyrite, pyrrhotite, sphalerite and galena. A grab sample from the ore dump at the upper of two adits contained 0.34 gram per tonne gold, 216 grams per tonne silver, 13.8 per cent zinc, 3.0 per cent lead and 0.70 per cent cadmium (Property File - Marshall Creek Copper Annual Report 1965, page 7). The shear zone is likely the southward extension of the shear zone hosting the Keystone showing (103P 115), 1700 metres to the north.

A 1.2 to 1.5 metre wide quartz vein, 240 metres to the south of the adits, lies along a dioritic/gabbroic dike and strikes 030 degrees. The vein contains a near massive lens of pyrrhotite. Samples are reported to assay trace gold, 51 grams per tonne silver (Minister of Mines Annual Report 1924, page 51) and trace gold and silver, 0.25 per cent nickel (Minister of Mines Annual Report 1927, page 70).

In 1927, the Theda Bara and Bebe Daniels claims were owned by Jones and Ingraham, of Alice Arm. An upper tunnel at 975 metres elevation is driven on a vein and is 15 metres long. About 6 metres lower in elevation than the upper tunnel, a second tunnel is driven on the vein for 6 metres.