The Letain deposit is located about 4 kilometres northeast of Letain Lake and about 80 kilometres east of the south end of Dease Lake.

The area of the Letain deposit is underlain by argillites, chert arenites, limestones and greenstones of the Mississippian to Triassic Cache Creek Complex (Mississippian to Triassic Kedahda Formation; upper Mississippian to Permian Nakina Formation). Tectonic emplacements of serpentinized peridotite and dunite, and diorite of upper Mississippian to Permian age occur within the Cache Creek Complex and are themselves considered part of the complex.

The sedimentary and volcanic rocks form a conformable assemblage striking northwest and dipping moderately northeast. An irregular body of serpentinite, 11 kilometres long by 3 kilometres wide, occurs within the volcano-sedimentary rocks approximately along the contact between sediments and volcanics. This body strikes northwest and dips 45 degrees northeast. Irregular ultramafic bodies extend to the southwest and southeast from the main body. Associated small bodies of fine-grained diorite cut the serpentinite or are marginal to it. Isolated rafts of country rock have been converted to gneisses, schists or marbles within the serpentinite.

The serpentinite is well-jointed in regular patterns. Compositional differences and varying magnetite content within the serpentinite result in differential weathering patterns, the colour changing from light yellow through to brown. Some of the banding is transverse to the trend of the serpentinite.

Mineralization consists of cross-fibre chrysotile asbestos occurring in fracture-related veinlets concentrated in an area near the centre of the serpentinite body. The fractures occur in two prominent sets: one striking 050 to 060 degrees and dipping steeply northwest, and the other striking 320 to 330 degrees and dipping nearly vertical. The serpentinite containing the fibre is generally medium to light green and weathers to a greyish pitted surface, the pits having been formed by the weathering out of bastite crystals. A thin section of this rock consists mainly of granular and mesh antigorite, pyroxene "ghosts" and abundant magnetite and chrysotile veinlets. The serpentinite without fibre is generally darker green, tends to weather brownish, and is harder and more brittle than the other type. It is commonly highly sheared with abundant slickensides. Vein fractures are not abundant, and most of those present contain picrolite or a massive apple-green material. A thin section of this rock consists essentially of feathery sheaves of antigorite with considerable carbonate, some actinolite and very minor magnetite.

The chrysotile veins range from microscopic to 3.1 centimetres wide, and most have one or more central partings. The partings are sometimes thin irregular films of magnetite or serpentine, but often they are 0.6 to 1.2 centimetre thick seams and brecciated masses of the light green massive chrysotile mentioned previously. Where the massive material is brecciated, it is frequently striped and striated parallel to the vein walls, but tiny multidirectional fractures within it contain asbestos fibres oriented perpendicular to the walls of the main vein. In some places the massive material grades laterally into good cross-fibre asbestos. Because of the partings, the fibre length is normally much less than vein widths. Most of the fibre is in the 0.3 to 0.6 centimetre range.

Diamond drilling has indicated three chrysotile asbestos fibre zones: the Main, West and East zones. The West zone is 183 metres northwest and the East zone is 183 metres southeast of the Main zone, respectively. The zones have a combined length of approximately 1500 metres with a maximum width of 200 metres, and extends to at least 300 metres downdip.

Possible geological reserves are 15,700,000 tonnes grading 4.7 per cent asbestos at a 3 per cent asbestos fibre cutoff to the 1600-metre level (Prospectus, Cassiar Mining Corporation, December 5, 1985).

In 1955, the claims were originally staked by Conwest Exploration Co. Ltd. In 1956, Conwest completed some open cuts and later conducted diamond drilling and bulk sampling. In 1957-58, the property was purchased by Cassiar Asbestos Corp.

In 1960, 28 claims were Crown granted (A, Bob, Rib, Ridge, Rex, Tent, Ton). In 1966, geological mapping, magnetometer surveys, bulldozer trenching and 6 diamond-drill holes were completed on the Main zone.

In 1970, trenching and site preparation was completed. In 1977-78, Cassiar Asbestos explored for asbestos in the area and drilled approximately 19 holes totalling 5200 metres.

In 1980, DuPont of Canada undertook a small sampling campaign looking for precious metals. In 1985, Getty Canadian Metals conducted work looking for the source of a gold anomaly.

First Point Minerals conducted an initial stage sampling program in the summer of 2007, and a regional mapping and sampling program in the summer of 2010 which collected stream sediments and rock samples. During the 2011 field season, First Point Minerals conducted exploration that involved tightly to loosely-spaced rock sampling and basic geological mapping.