Mactung Project

Boundary between NWT & Yukon, Canada

The Mactung Project is one of the largest and highest-grade tungsten projects in the world.


The Mactung Project, the largest high-grade tungsten deposit in the world, was acquired by Fireweed in 2022.  It is located adjacent to the Macpass Project and accessed via the Macmillan Pass aerodrome and the North Canol Road.  The project area, which straddles the Yukon-Northwest Territories boundary, is within the traditional territories of the Kaska Dena Nation and the First Nation of Na-cho Nyäk Dun and in the Sahtu Settlement Area.  Extensive drilling, engineering, metallurgy, geotechnical, and environmental studies have been undertaken previously to support a positive Feasibility Study (2009) and environmental and socio-economic assessment through the Yukon Environmental and Socio-economic Assessment Board (2014).
A 2023 Technical Report announced updated mineral resources for Mactung.  The mineral resource totaled 41.5 Mt Indicated Resource at 0.73% WO3 and 12.2 Mt Inferred Resource at 0.59% WO3. It is estimated that there is the potential for an Exploration Target at Mactung of between 2.5 and 3.5 Mt at a grade of between 0.4 and 0.6% WO3 in addition to the current Mineral Resources disclosed (see Fireweed news release). These results make it the world’s largest high-grade tungsten deposit.
  • Five holes were completed by Fireweed in 2023 to support metallurgical studies and improve definition.
  • ~650 m of untested strike length between the resource and where the skarn units crop out on Mt. Allen provide exploration upside.
  • Updated resource by Fireweed metals in 2023 of 41.5 Mt at 0.73% WO3 indicated and 12.2 Mt at 0.59% WO3 inferred.


  1. All mineral resources have been estimated in accordance with Canadian Institute of Mining and Metallurgy and Petroleum (“CIM”) definitions, as required under National Instrument 43-101 (“NI43-101”).
  2. Mineral resources are reported in relation to a conceptual pit shell and underground mining volumes to demonstrate reasonable prospects for eventual economic extraction, as required under NI43-101; mineralization lying outside of the pit shell or underground volumes is not reported as a mineral resource. Note the conceptual pit shell and underground volumes are used for mineral resource reporting purposes only and is not indicative of the proposed mining method; future mining studies may consider underground mining, open pit mining or a combination of both. Mineral resources are not mineral reserves and do not have demonstrated economic viability. Mineral resource estimates do not account for mineability, selectivity, mining loss and dilution. All figures are rounded to reflect the relative accuracy of the estimate and therefore numbers may not appear to add precisely.
  3. Open pit (OP) mineral resources are reported at a cut-off grade of 0.25% WO3. Underground (UG) mineral resources are reported at a cut-off grade of 0.5% WO Cut-off grades are based on a price of US$240 per mtu of WO3 concentrate and a number of operating cost and recovery assumptions (see Table 5).
  4. Inferred mineral resources are considered too speculative geologically to have economic considerations applied to them that would enable them to be categorized as mineral reserves. There is also no certainty that these inferred mineral resources will be converted to the measured and indicated categories through further drilling, or into mineral reserves, once economic considerations are applied. The Inferred Mineral Resource in this estimate has a lower level of confidence than that applied to an Indicated Mineral Resource and must not be converted to a Mineral Reserve. It is reasonably expected that the majority of the inferred Mineral Resource could be upgraded to an Indicated Mineral Resource with continued exploration.
  5. A metric tungsten unit (mtu) is 10 kilograms of tungsten trioxide (WO3).

Mactung is a tungsten skarn deposit located on the eastern margin of the Selwyn basin in the Canadian Cordillera’s Tombstone-Tungsten Belt (TTB). The mid-Cretaceous TTB spans Alaska, Yukon, and NWT, and hosts many other significant mineral deposits.

The tungsten mineralization at Mactung is comprised mostly of scheelite (CaWO4) and is dominated by calcic mineral assemblages associated with abundant pyrrhotite that developed within permeable limestone units of the Cambrian-Ordovician host rocks.


Fireweed Metals Files Technical Report for its Mactung Project on SEDAR

Fireweed Announces Near-Term Plans for Mactung Project

Fireweed Metals Announces Mineral Resources for the Mactung Project: the Largest High-Grade Tungsten Deposit in the World*

Fireweed Announces Signing of Definitive Agreement on Mactung Project



Mactung 43-101 Resource Report