Chieftain Prepares to Publish Feasibility Study in January 2013

After publication of the feasibility study, the Company will continue its optimization work in the areas of improving its copper concentrates, examining further infrastructure and materials handling improvements, resource optimization and exploration potential to its Tulsequah Chief project. The Company expects to embark on partner and project finance discussions early in the New Year to arrange construction financing.

Gordon Doerksen of JDS Energy & Mining Inc., a Qualified Person under NI 43-101, has reviewed and approved the technical content of this news release.

The news release published on December 12, 2012, at 8:15 a.m. EST entitled “Chieftain Announces Robust Tulsequah Chief Feasibility Study Results” is shown below in its entirety reflecting the above-mentioned changes:

Chieftain Announces Robust Tulsequah Chief Feasibility Study Results

Highlights of the Tulsequah Chief Feasibility (Table 1)

Victor Wyprysky, President and CEO commented: “We are pleased to deliver a feasibility study demonstrating robust economics for Tulsequah. The NPV8% of $192.7 million represents a pre-tax Net Asset Value of approximately $13.24 per share and average annual EBITDA at full production of $120.4 million or $8.28 per share based on the current outstanding shares. This study will enable Chieftain to finalize project financing and plan construction start-up. The project will bring significant benefits for the Taku River First Nation, the Atlin community and British Columbia, and Chieftain is fully committed to continue to build strong relationships with the community while developing the project in a socially and environmentally responsible manner within the guidelines of the Atlin-Taku Land Use Plan.”

Resources and Reserves

The mineral resource estimate (Table 2) was updated and classified using logic consistent with the Canadian Institute of Mining and Metallurgy (“CIM”) definitions referred to in National Instrument 43-101 into Measured, Indicated, and Inferred Mineral Resources. The mineral resource estimate was developed using industry-accepted methods with GEMS software in blocks sized 5 m x 5 m x 4 m. For the purpose of resource estimation, all assay intervals within the mineralized units were composited to two metres and grades were capped prior to estimation. Zinc was capped at 30%, lead and copper at 10%, gold at 25 g/t and silver at 600 g/t for the resource estimate.

The reserve estimate is summarized in Table 3 below. The probable reserve totals 6.45 Mt of minable material.

Table 3. Tulsequah Chief Mineral Reserves

The Underground Mine

A new underground mine, adjacent to and beneath old workings that were previously operated by Cominco Ltd. from 1951-57, will be developed through the existing 5200 and 5400 Level adits and will be used as the primary access to the mine for all personnel, mine services, equipment and supplies.

The new mine will operate as a ramp-entry truck haulage operation via a spiral ramp that will be developed to a vertical depth of 750 meters with mining levels located at 30-meter vertical intervals. Sub-level stoping will be the primary mining method with a minor amount of mechanized cut-and-fill stoping. Paste backfill and unconsolidated loose waste rock will be used for replacement of mined voids for both methods. Where backfill walls will be exposed by future adjacent mining, additional cement will be added to the paste backfill for strength.

Metallurgy

A process plant was designed for the Tulsequah Chief project to process massive sulphide mineralization at a rate of 2000 t/d. The process facility will consist of a primary crushing plant, conveyor corridors; mill feed storage bin, grinding and flotation plant, effluent treatment plant and backfill plant. The process plant will operate two shifts per day and 365 days per year with an overall availability of 92%. The process plant will produce copper, lead and zinc concentrates and gold-silver dore as outlined in the following table predicted metallurgical response.

Table 4. Predicted Metallurgical Response

Access and Transportation

A new 128 kilometer long, Forestry approved 5m wide road will be constructed from the end of the Warm Bay road, south of Atlin, BC, to the Tulsequah Chief Mine site. The concentrates produced during operations are anticipated to be trucked to the Skagway terminal facility where improvements to the facility are planned to handle the storage and transfer of Chieftain’s concentrates. Supplies will be transported to the mine by road utilizing the backhaul portion of the trip.

Infrastructure

All surface buildings will be located in close proximity to the mine, including the mineral process building, a 210-person camp and kitchen/dining facility, a two-story administration/mine dry building, which includes the ambulance building, an LNG/diesel-generated power plant, and the maintenance/warehouse facility for surface equipment.

The mine will operate on varying rotating schedules including four days on/three days off, two weeks on/two weeks off, and two weeks on/one week off. The schedules reflect the various work schedules required to cover the tasks on site. A 1,050 m long airstrip has been constructed approximately 2 km north of the mine near Shazah Creek.

A 3.0 Mt capacity tailings facility is designed and will be constructed approximately 5 km north of the mine in the valley of Shazah Creek. De-pyritized tailings will be transported in the form of a dense slurry by pipe.

Capital Costs

The initial capital requirement for the Project is estimated to be $439.5 M, as detailed in Table 5.

Table 5. Pre-production Capital Costs

The Project has a total sustaining capital requirement of $64.0 million. Sustaining capital is required for extension of the main ramp to depth, mobile equipment rebuilds and replacements, and capital improvements.

Reclamation/Closure & Salvage Costs

Total reclamation/closure and salvage costs have been estimated as follows:

Table 6. Reclamation/Closure & Salvage Costs

Operating Costs

Total operating costs for the Project have been estimated as follows:

This cost represents the Life of Mine Cash Cost of the Project, from years 1 – 9 inclusive.

Financial Analysis and Sensitivities

Using the three year trailing average commodity prices, the study yields a pre-tax NPV8% of $192.7 million and an IRR of 16.5% with a payback period of 4.3 years and a post-tax NPV8% of $138.7 million and an IRR of 14.7% with a payback period of 4.3 years.

Sensitivity tables for changes in capital costs, operating costs, metal prices, and discount rates are shown below. The Project’s NPV is most sensitive to grade, metal prices, followed by operating costs, and least sensitive to capital costs.

Table 9. Project NPV Sensitivity to Discount Rate

Project Schedule

Project construction is expected to commence in the Spring of 2013, subject to project financing. Site earthworks are expected to begin in Q3 2013, mill and site construction in Q4 2014, and tailings construction in Q1 2015, with commissioning and production beginning in Q4 2015.

Technical Report

A NI 43-101 Technical Report will be filed within 45 days on SEDAR and will be available at that time on the corporate website.

Qualified Persons

The technical content of this release was reviewed by Keith Boyle, P. Eng., Chief Operating Officer of Chieftain Metals Inc. and qualified person under NI 43-101.

The Feasibility Study was conducted under the overall review of Gordon Doerksen, P. Eng. of JDS Energy and Mining Inc. of Vancouver, British Columbia, and serves as Principal Author of the Technical Report.

The following Independent Qualified Persons have assumed authorship of this report:

About Chieftain Metals Inc.:

Forward-Looking Information:

This press release includes certain “forward-looking statements” within the meaning of the Ontario Securities Act or other laws or regulations. All statements, other than statements of historical fact, included herein, including without limitation, statements regarding potential mineralization, mineral resources or reserves, exploration results, future plans and objectives of Chieftain Metals Inc. are forward-looking statements that involve risks and uncertainties. There can be no assurance that such statements will prove to be accurate and actual results and future events could differ materially from those anticipated in such statements.