The Cogburn prospect is located approximately 500 metres east of Talc Creek, along Daioff Creek. The site is approximately 24 kilometres north of Harrison Hot Springs, 8 kilometres east of Harrison Lake and 120 kilometres east of Vancouver. Access is by logging roads up the east side of Harrison Lake, Cogburn Creek, then Talc Creek. The area consists of steep mountains with heavily treed slopes and abundant clearcuts.

The area of the Cogburn (Ni) prospect is underlain by a metamorphic package of Paleozoic and/or Mesozoic rocks, possibly correlative with the Permian-Jurassic Hozameen Complex, that were metamorphosed in the Cretaceous. These rocks comprise quartz-muscovite-garnet schist and metavolcanics consisting of hornblende and hornblende feldspar schists. The regional foliation strikes from 320 degrees with a 45-degree northeast dip to 290 degrees with an 85-degree northeast dip and is generally parallel to layering, although some foliation across layering has suggested the occurrence of isoclinal folding. Intimately associated with these Hozameen-derived rocks is a northwest-trending fault-bound body of Mesozoic and/or Paleozoic serpentinized pyroxenites and peridotites stretching approximately 10 kilometres.

The country rocks are intruded by quartz diorite plugs and dikes associated with the Late Cretaceous Spuzzum pluton, and Monger has mapped a small stock of Oligocene granodiorite just north of the prospect (GSC Map 41-1989).

Mineralization identified on surface and in drillholes consists of up to 4 per cent pyrrhotite, with trace chalcopyrite and pyrite. Pyrrhotite occurs widely but sparingly in the ultramafics. It occurs as grains and blebs interstitial to pyroxene crystals, as scattered grains along microshears and as narrow fracture veinlets less than a few centimetres in length. Chalcopyrite has been found sparsely disseminated in the pyrrhotite. Pyrite is sparingly distributed through most of the rocks of the area but is lacking in parts of the ultramafic body. Pentlandite has been reported to occur with the above minerals as disseminations (Geology, Exploration and Mining in BC 1975, p. 74). Samples of mineralized rock yielded 0.19 to 0.22 per cent nickel and trace copper (Geology, Exploration and Mining in BC 1971, p. 262).

Geological mapping was conducted in the area by the Geological Survey of Canada in 1924, 1926, 1935, 1938 and 1939. In 1969, B.E. Lowes conducted additional mapping as part of a thesis for the University of Washington. No record of exploration exists prior to 1969.

In 1969, the Nickel Syndicate—a joint venture between Giant Explorations Limited and Giant Mascot Mines Limited—staked the Ni claims and began a reconnaissance-style exploration program. Between 1969 and 1975, the syndicate completed regional geological mapping, prospecting, stream sediment sampling, drilling, an airborne magnetic survey, detailed grid exploration (soil geochemistry, magnetic geophysics and rock sampling) and induced polarization geophysical surveys. The airborne magnetic survey was completed in 1970 and consisted of 539.13 line kilometres (335 line miles) flown over an area of 220 square kilometres (85 square miles). Six target areas were defined from the magnetic survey results. Grids were cut over each target area and used for geological mapping, ground magnetic surveys and soil and rock-chip sampling. The majority of the work was concentrated on an area near the junction between Talc and Daioff creeks. In 1971, induced polarization surveys were used to define potential drill targets. Twenty diamond drill holes totalling 1756 metres (5760 feet) were drilled to test anomalies on two grid areas. Results of the drilling were never reported and core logs, assays, drillcore and most hole location data are missing. Reports from the time indicate that a major tonnage of low-grade nickel mineralization had been discovered through initial drilling and widespread surface sampling of the property. The deposit was more than 609.6 metres (2000 feet) in length and 243.84 metres (800 feet) in width, with a 213.36-metre (700-foot) vertical range. Initial estimates indicated a yield of 907 718 474 tonnes per 152.4 metres depth (100 000 000 short tons per 500 feet depth; George Cross Newsletter, September 1, 1971). Chip sampling over a 32.37-hectare (80-acre) area returned average grades of 0.22 per cent nickel (Assessment Report 28695). In 1971, a geologist from the provincial government collected 10 chip samples from the deposit area. Analysis of the chip samples generally confirmed a grade of 0.19 to 0.22 per cent sulphide nickel plus approximately 0.02 per cent silicate nickel (Geology, Exploration and Mining in BC, 1971). In 1975, additional lines were cut on one of the grids and an electromagnetic survey was completed.

J.P. McGoran conducted prospecting on the Ni 258 claim, 500 metres east along Daioff Creek, for Fleck Resources Limited in 1985. The purpose of the prospecting was to determine if platinum metals were present in the area. Two rock samples and four gravel samples were collected. Assays of two rock samples and one gravel sample returned insignificant results for platinum (Assessment Report 14402).

Leader Mining International Incorporated acquired the Cogburn property in 2001 and conducted exploration through its wholly owned subsidiary North Pacific Alloys Limited. Initial exploration consisted of 35 rock samples collected from the Emory zone and Daioff area. Crest Geological Consultants Limited followed up with additional sampling in the region surrounding Cogburn and Talc creeks. In total, 14 samples were collected: three samples from the southeast extension of the northern ultramafic body, six samples from the northwest end of the main ultramafic body, two samples from the outcrop along the northern margin of the main ultramafic body and three stream sediment samples. Results of the geochemical sampling corroborated the results previously obtained by Leader Mining and indicated a widespread distribution of magnesium-rich ultramafic rocks and persistent low-grade nickel sulphides throughout. The geochemical sampling results prompted Leader Mining to undertake an exploration program to identify the magnesium potential of the ultramafic silicates. Further exploration revealed high-grade magnesium over an extensive area and prompted the company to redirect the focus of the project from nickel to magnesium. Crest Geological Consultants Limited was hired to conduct a two-phase magnesium exploration program consisting of geological mapping and rock sampling over two ultramafic bodies.

In December 2001, Leader Mining International Incorporated completed a total of 1360 metres in 23 core drillholes. Holes within the Emory zone yielded consistently higher magnesium grades (greater than 25 per cent magnesium) with lower impurity levels (Canadian Stockwatch, January 7, 2002). In all, 26 diamond drill holes totalling 1360 metres were completed over a 7-kilometre strike length of an ultramafic dunite body. Drilling results indicated that the Emory zone, on the western side of East Talc Creek, had the best potential because it had the highest magnesium grade and the least contamination from elements such as calcium, iron, sulphur, boron and nickel. That year, Hatch Limited was commissioned to prepare a scoping study on the development of a magnesium reduction plant in the area. The report, released in February 2002, recommended the project progress to feasibility level activities.

In 2002, Leader began a deposit development drilling program in the Emory zone. Thirty-four diamond drill holes were completed, totalling 1904 metres and ranging in depth from 50 to 80 metres. Five drillholes were unable to reach their target depth due to faulting, and 617 core samples were collected and sent for analysis. Bench-scale testing of the serpentinized peridotite showed that the rock is amenable to chemical leaching by a proprietary method to produce a magnesium chloride solution that can be processed by conventional methods (Press Release, Leader Mining International Inc., December 23, 2002).

In 2003, Hatch Limited released a feasibility study indicating that the deposit has the potential to become a mine because of its large size, high magnesium grade, low impurity levels, favourable metallurgy and proximity to infrastructure. The project was considered feasible and economically viable if developed as a quarry over the Emory zone with ore shipped to a 131 000-tonne per year magnesium reduction plant located at Ruby Creek near Highway 7.

In 2004, project development work was conducted through North Pacific Alloys Limited, a subsidiary of Leader Mining International Incorporated. A project description was submitted to the BC Environmental Assessment Office in November 2004 to initiate project review.

North Pacific Alloys Limited continued with its development plans for the deposit in 2005, when it announced that it was looking for a company to be project operator or owner. That same year, the company decided that, in addition to developing the Cogburn magnesium project, it would restart exploration on the property for nickel, copper and platinum group elements. Between 2005 and 2006, work on the property consisted of road development and maintenance, airborne geophysics, surface sampling and the extraction of a 3-tonne bulk sample of magnesium ore. In 2006, Leader continued working on surface land acquisition and project development at the proposed plant site near Ruby Creek, BC environmental assessment permitting. Further development of the Cogburn magnesium project was abandoned after Leader Mining ceased operations in 2006 and ownership of the claims was transferred to John A. Chapman and Gerald G. Carlson.

In 2011, Coast Mountain Geological Limited conducted a two-phase exploration program on the Cogburn property for the purpose of delineating potential areas of nickel, copper and platinum group element mineralization. A 21-line kilometre grid was surveyed and cut and a three-dimensional induced polarization survey was completed over the entire grid area. The induced polarization survey generated a significant number of chargeability anomalies and a very large and complex conductive zone. Further exploration of the anomalies was recommended.