The Strangward A is a showing of copper mineralization, 8 kilometres northwest of Mount Mary Henry in the mountainous Muskwa Ranges of the Northern Rocky Mountains, 15 kilometres south-southeast of the settlement of Summit Lake on the Alaska Highway (Vail, J.R. (1957) - Thesis, Geological Map).

The occurrence is in a region known as the Tuchodi Anticline, an open fold structure which formed on a ramp of a major northeast-verging thrust (Geological Society of America, Geology of North America, Volume G-2, pages 639, 642). Exposed in the anticline are rocks as old as Middle Proterozoic (Helikian), and these are flanked by Paleozoic rocks (Geological Survey of Canada Map 1343A). All belong to Ancestral North America (Geological Survey of Canada Map 1713A). The Middle Proterozoic rocks are pre-Windermere Supergroup, and are known as the Muskwa Assemblage (Geological Society of America, Geology of North America, Volume G-2, page 111). This assemblage of carbonate and clastic rocks has been divided into seven formations. From its location, the Strangward A showing is apparently close to the contact between the Chischa and the overlying Tetsa Formation (Vail, J.R. (1957) - Thesis; Geological Survey of Canada Memoir 373, Paper 67-68). The Chischa Formation is composed of dolostone and quartzite, and the Tetsa Formation consists of mudstone and sandstone. Locally, the original Strangward claims are underlain by siliceous limestone, feldspathic quartzite and carbonaceous sandstone (Menzies, M.M. (1951) - Thesis).

The Strangward A occurrence comprises a number of small showings, all in quartz-carbonate veins (Vail, J.R. (1957) - Thesis). The veins fill numerous parallel shear fractures of small displacement, associated with an 85-metres wide, vertical, northwest-striking fault zone. The veins are generally narrow, 30 centimetres on average, with the widest being about 1 metre. They can be traced for varying distances, up to about 180 metres. A vein about 1 kilometre away may be a continuation of the same system.

The veins comprise quartz or calcite or both, and locally contain centimetre-scale lenses of massive chalcopyrite, with lesser bornite and chalcocite. Malachite is common in the veins and wall rocks, and secondary covellite fills small fractures cutting the sulphides.

In one place, a 6-metres long breccia zone in carbonaceous sandstone is cut by numerous mineralized veins and veinlets. A 60-centimetre channel sample in this material assayed 4.35 per cent copper (Menzies, M.M. (1951) - Thesis, page 40). Other samples give very high copper assays, but they are obviously heavily mineralized.