The Lake mine was first staked in 1905 as the Margery claims and by 1908 was exposed in several open cuts and short tunnels (Wright and Wright, 1905, 1908). One ton of ore was shipped in 1920 (Gault and others, 1953). It was still active in 1925 when it was restaked as the Lake claims and was active until at least 1927 (Buddington, 1926, Smith 1930a, Smith 1930b). It was restaked in 1965 and then again in 1978 by the Pacific Coast Molybdenum Co. who held the claims until 1986 (Still and others, 2002). The workings consist of three adits, numerous trenches, and surface stripping; most probably date to before 1927.

The mineralization occurs along a major fault zone that strikes N25 to 35 E and dips 70 to 90 degrees to the southeast (Gault and others, 1953; Still and others, 2002) The rocks in the vicinity are dark-colored phyllite and slate, quartzite, chlorite schist, and biotite schist that are about 2000 feet west of large Cretaceous biotite tonalite to granodiorite pluton (Gault and others, 1953; Brew, 1997). The fault zone is 5 to 12 feet wide and has been exposed in the adits and numerous trenches and pits for about 1,450 feet. The mineralization is all within the fault zone and consists of quartz breccia with major galena and lesser sphalerite, pyrite, and chalcopyrite, as well as as massive sulfide bands up to 0.5 feet thick, and sulfide-bearing quartz veinlets and pods.