The Strangward B is a showing of copper mineralization, 7.5 kilometres west-northwest of Mount Mary Henry in the mountainous Muskwa Ranges of the Northern Rocky Mountains, 20 kilometres south 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 B showing is probably in either the Chischa or overlying Tetsa Formation, or possibly both (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.

The Strangward B showing is actually closely associated with a basic dyke, specifically the west contact of the eastern of two parallel dykes spaced 60 metres apart (Vail, J.R. (1957) - Thesis). Pockets of chalcopyrite and chalcocite occur sporadically along this dyke contact. Both dykes strike 335 degrees and are vertical. They have been traced for at least 6.5 kilometres to the northwest. At their southeastern extremity they branch into several smaller dykes. Regionally, these basic or gabbroic dykes are known to be Precambrian because they are truncated by a sub-Cambrian unconformity (Geological Survey of Canada Memoir 373).

Over a 2.5-kilometres long segment of the dykes there are a number of gossans attributed to the weathering of pyritic replacement. Associated with this was a supergene enrichment which altered primary chalcopyrite and bornite to chalcocite and covellite (Vail, J.R. (1957) - Thesis).