The True Blue deposit is located on the west bank of Monashee Creek (previously known as the south fork of Cherry Creek) about 30 kilometres east of Lumby.
The small silver lode was discovered in 1863 and a small amount of ore was rawhided to the coast for processing in 1864 by Cherry Creek Silver Mining Co. In 1877, a "quartz ledge" was discovered on the opposite side of the creek from the original workings. The True Blue (Lot 254), Royal (Lot 255) and Batouche (Lot 256) claims were Crown granted to Hidden Treasure Mining Co. in 1889. By 1898, a tunnel 18 metres long was completed on the Hidden Treasure and Grand Times claims. In 1899, a 55-metre tunnel was located on the Grand Times claim. In 1905, a tunnel 15 metres long exposed "very rich" ore. In 1992, the workings were caved but mapping and sampling were conducted in the area of the old workings.
The area is underlain by volcanic and sedimentary rocks of the Upper Triassic to Lower Jurassic Nicola Group. The bedding strikes northwest and dips slightly south. Lithologies comprise volcanics, tuffs and argillite.
The old workings occur in argillite with quartz. The mineral- ization comprises argentiferous galena, tetrahedrite or freibergite with galena and sphalerite. The mineralization occurs in quartz hosted in shale or slate. Assays were reportedly as high as 100,000 grams ($2000/ton) per tonne silver with some gold (Minister of Mines Annual Report 1877, page 405). In 1992, a well-mineralized grab sample taken from the dump assayed 0.625 gram per tonne gold, 306.9 grams per tonne silver and 6.52 per cent zinc (Assessement Report 22223). Quartz at other localities in the area is not mineralized but the argillite in the footwall may host mineralization.