The Molly Lake area is underlain by a marginal section of the Cretaceous Horsethief Batholith and sediments of the Middle Proterozoic Dutch Creek Formation (Purcell Supergroup).

The intrusive rock is a coarse-grained, greyish purple, quartz monzonite which is typical of the contact zone for about a 60 metre width. The Dutch Creek Formation is a dark reddish brown, biotite-rich hornfels, which is cut either by abundant white aplite dikes or by numerous quartz veins in different sections.

Lying in the hornfels just north of the contact, the Molly Lake II showing is composed of two zones. A 213-metre wide aplite dike zone, adjacent to the contact, is slightly mineralized. A quartz vein zone, well mineralized, occurs 150 metres further north and is referred to as the proper of the Molly Lake II showing.

The aplite dike zone contains voluminous aplite dikes and irregular bodies that contain rare fine specks of molybdenite as well as quartz-rich vugs with molybdenite rosettes. At a point where these aplite dikes and bodies decrease abruptly in abundance, numerous molybdenite-bearing quartz veins cut across the fine-grained micaceous hornfels.

There are three types of molybdenite mineralization associated with the quartz veins: 1) molybdenite occurs as fissure-filling between the quartz veins and the host hornfels, 2) molybdenite specks are formed along lengthwise seams in quartz veins, 3) flakes of molybdenite are disseminated in a five millimetre biotite-rich band in hornfels, parallel to the neighboring quartz vein.

The quartz veins are mostly 5 centimetres thick, reaching 30 centimetres in some places. The predominant attitude strikes 045 degrees and dips 60 degrees southeast. The spacing of the veins varies from 1.5 to 9 metres. The quartz vein zone is mineralized in an area of at least 300 by 150 metres. Some of the mineralized veins were traced away from the contact for 300 metres until they became barren.

In 1971, Canadian Johns-Manville completed further surveys on its Slide group of claims and staked the Bev claims to cover newly found molybdenite showings, the Molly Lake showings. See also Molly Lake 1 (082KNE050). A total of 77 geochemical samples were collected from the Bev area (Assessment Report 3581). The company did further mapping in 1972 and collected 271 samples from the Bev claims. In 1973, a further examination of the property was reported by the company (Assessment Report 4613).