Excelsior Releases Positive Prefeasibility Study Demonstrating $1.24 Billion Pre-Tax NPV and 59.7% Pre-Tax IRR for the Gunnison Copper Project

PHOENIX, ARIZONA--(Marketwired - Jan 17, 2014) - Excelsior Mining Corp. (TSX VENTURE:MIN)(FRANKFURT:3XS)(OTCQX: EXMGF) ("Excelsior" or the"Company") is pleased to announce the results of a comprehensive Prefeasibility Study ("PFS") on the North Star Deposit of the Gunnison Copper Project, located in southern Arizona. The PFS was completed by M3 Engineering & Technology Corporation ("M3") of Tucson, AZ and is effective as of January 13, 2014. The National Instrument ("NI") 43-101 compliant Report (the "Report") summarizing the results of the PFS will be filed on SEDAR and Excelsior's website within 45 days of this news release. Results of the PFS disclosed in this press release are in USD and pre-tax (except where otherwise indicated).

Highlights of the North Star Gunnison Copper Project PFS "Acid Plant" option include:

• Pre-tax Net Present Value ("NPV") of $1.24 billion (after-tax $0.826 billion) at a 7.5% discount rate (using a copper price of $2.75/lb)
• Pre-tax Internal Rate of Return ("IRR") of 59.7% (after-tax 44.7%)
• Pre-tax payback period of 1.8 years (after-tax 2.4 years)
• Initial estimated capital cost (excluding sustaining capital) of $284.74 million
• Average life-of-mine operating costs of US$0.68 per pound
• Other costs of $0.12 per pound, including Royalties of $0.029 per pound
• Annual production rate of 110 million pounds of copper for the first 14 years, then declining for a 20 year mine life, with a total of 1.682 billion pounds of copper produced over the life of the mine.

"The completion of a positive Prefeasibility Study is a significant de-risking event in Excelsior's development and we are very pleased with the results. The results surpass the robust economic potential indicated by the 2011 Preliminary Economic Assessment and support copper extraction of the North Star Deposit through in-situ recovery with the potential to generate exceptional financial returns," says Mark J. Morabito, Chairman of Excelsior. "With initial production expected to commence in Q4 2016 we are looking forward to beginning the next phase of development."

Commenting on the results, President and CEO, Stephen Twyerould said, "With the completion of this major milestone, the commercial case for the Gunnison Copper Project has grown even stronger. The Prefeasibility Study has confirmed the robust economics and technical viability for what has the potential to be one of the lowest cost copper producers in North America."

Financial Analysis

As highlighted in the tables below, the PFS demonstrates robust project economics in both the "Acid Plant" and "Non-Acid Plant" scenarios, with the Acid Plant option adding an additional $174.2 million to the project pre-tax NPV. Based on an initial annual production rate of 110 million pounds, the PFS indicates that including an Acid Plant as a component of the project, generates a pre-tax NPV of $1.24 billion, at a cash flow discount rate of 7.5%. The pre-tax IRR for this option is 59.7% with a payback period of 1.8 years. On an after-tax basis, the PFS shows an NPV_7.5 of $825.83 million, IRR of 44.7% and a payback period of 2.4 years.

Without an Acid Plant, the project still has a significant pre-tax NPV_7.5 of $1.06 billion and an IRR of 61.4%, (after-tax NPV_7.5 of $721.41 million and an IRR of 46.1%). The after-tax analysis is based on a number of assumptions which will be fully set out in the Report. The level of accuracy of the PFS is considered to be +/-20%.

Both scenarios used the following parameters over the 20 year life of the project:

• copper selling price of $2.75 per pound,
• total copper recovery of approximately 47% (based on a combination of metallurgical recovery and sweep efficiency),
• average of 8.14 pounds of acid consumed for every pound of copper produced,
• acid price of $45.70/ton for the Acid Plant option and $125/ton for the Non-Acid Plant option,
• state tax rate of 6.97%, and
• a federal tax rate of 35%.

Total initial capital expenditures for the "Acid Plant" option (including contingency) are estimated at $284.74 million. Sustaining capital, which includes the acid plant built in year three, water treatment facilities and production wellfield are estimated at $602.4 million. Net closure costs are estimated at $44.5 million. For the "Non-Acid Plant" option, total initial capital expenditures (including contingency) are estimated at $284.74 million. Sustaining capital, which includes the water treatment facilities and production wellfield are estimated at $528.8 million. Net closure costs are estimated at $42.3 million.

The PFS assumes a copper selling price of $2.75/lb. Average life-of-mine operating direct cash costs are estimated at $0.68/lb for the "Acid Plant" option and $0.98/lb for the "Non-Acid Plant" option.

Mineral Resources and Mineral Reserves

Mineral Resource Estimate

The mineral resource estimate for the North Star Deposit is based on results from 88 drill holes totalling 129,272 feet (ft). The estimate is consistent with the CIM definitions referred to in NI 43-101. Mr. Herb Welhener, RM-SME, of Independent Mining Consultants, Inc. ("IMC") of Tucson, Arizona is a Qualified Person as defined by NI 43-101 and is responsible for reviewing and approving the mineral resource and mineral reserve estimates and the QA/QC associated with the estimates. Mr. Welhener is independent of the Company. He has verified, reviewed and approved the technical disclosure contained in the 'Mineral Resources and Mineral Reserves' section of this news release and the underlying sampling, analytical and test data. The mineral resource estimate has been prepared using a 0.05% Total Cu cut-off grade and is effective as of January 13, 2014.

The mineral resource estimate is contained within a block model of the North Star deposit covering a surface area of 3.30 square miles and to a maximum depth of 2,575 feet below the topographic surface.

The major geologic formations and oxidization types are incorporated into the block model based on the drill hole intercept data. The total copper grades are estimated using an ordinary kriging estimation technique from 25 ft drill hole composite data. The grade estimate for the sedimentary units uses a 700 ft circular by 50 ft search distance dipping 30 degrees east to parallel the general dip of the sedimentary units. The grade estimation respected the contacts of the various sedimentary units. The 700 ft distance is 70% of the variogram range. The total copper grades in the non-sedimentary units were estimated using a 500 ft spherical search. No copper grades are estimated in the overburden or un-mineralized rock units. Copper grade estimates based on eight or more holes are classified as Measured, grades based on three to seven holes are Indicated and grades based on less than three holes are Inferred.

All samples are prepared from manually split half-core sections on site in Arizona. Split drill core samples are then sent to Skyline Assayers & Laboratories in Tucson, Arizona for Total Copper and Sequential Copper analyses. Standards, blanks, and duplicate assays are included at regular intervals in each sample batch submitted from the field as part of an ongoing Quality Assurance/Quality Control Program.

Mineral Reserve Estimate

The PFS mineral reserve is based on an economic analysis of the mineral resource using the costs developed during the 2011 PEA, test work to estimate the recovery factors and a $2.75/lb copper price. The economic optimization was performed on Measured and Indicated Resources. EBIT (earnings before interest and tax) was calculated on a block by block basis based on economic parameters. Consistent blocks (in vertical and horizontal directions) at a cut-off grade of 0.05% total Cu with a positive EBIT values that were greater than the capital cost of drilling and establishing the wells required for each column of blocks were included in the reserve. Total Cu% was selected for the mineral reserve estimate. The mineral reserve was estimated after applying engineering and operational design parameters which removed the thinner and deeper portions of the mineral resource. Internal dilution has been included in the final mineral reserve estimate. IMC is of the opinion that the mineral reserve estimate derived in this PFS reasonably quantifies the economical ore mineralization of the North Star Deposit. The reserve estimate is as of January 13, 2014 and the mineral reserves presented in the table below are included in the mineral resource estimate set out above.

Excelsior is not aware of any environmental, permitting, legal, title, taxation, socio-political, marketing or other issues which may materially affect the mineral resource and mineral reserve estimates. The production schedule of the PFS recovers approximately 47% of the mineral reserve.

Project Summary

The Gunnison Copper Project is located in a remote section of Cochise County about 65 miles east of Tucson, Arizona in the Johnson Camp Mining District. The property is within the copper porphyry belt of Arizona. The focus of the project is the North Star deposit, which currently hosts a total Measured and Indicated mineral resource of 3.91 billion pounds of copper (683 M tons at 0.29%) and an Inferred mineral resource of 1.40 billion pounds of copper (338 M tons at 0.21%). The Probable mineral reserves for the North Star Deposit are 3.61 billion pounds of copper (632 M tons at 0.29%). This oxide and transition portion of the mineral reserve has the potential to be mined using in-situ recovery methods.

The proposed project, as stated in the PFS, includes the following components:

• The North Star copper deposit.
• The Wellfield including injection, recovery, observation and perimeter wells and related infrastructure.
• The acid plant, including sulfur and sulfuric acid handling and cogeneration plant.
• Processing infrastructure including a Solvent Extraction/Electrowinning ("SXEW") Plant and pipe corridors.
• Water treatment facility and facility ponds.
• Ancillary infrastructure to support the mine and process plant (electrical substation, administration/office buildings and transmission lines).
• The rail infrastructure and rail car storage.

The proposed project will produce 110 million pounds of copper per year for the first 14 years, then declining to year 20. Processing will take place at the Gunnison site and will involve solvent extraction and electrowinning to produce pure copper cathode sheets.

Technical Report and Qualified Person

An NI 43-101 Technical Report will be filed on SEDAR and on Excelsior's website within 45 days of the date of this news release. The Report will consist of a summary of the Prefeasibility Study. The Report is being prepared under the supervision of Conrad Huss, P.E. of M3 Engineering & Technology Corporation, Tucson, Arizona, who is a qualified person that is independent of the Company. The Report will also receive contributions from the following additional qualified persons, who are also independent of the Company:

• Dr. Ronald J. Roman of Leach, Inc., Tucson, Arizona (metallurgy and leaching recovery).
• Peter Lenton, P.E. of Haley & Aldrich, Phoenix, Arizona (hydrology, extraction methods, production schedule).
• Peter Lemke, P.E. of Golder Associates Inc., Lakewood, Colorado (water treatment and related facilities).
• Mr. Herb Welhener, RM-SME, of IMC of Tucson, Arizona (geology, mineral resource and reserve).

Each of the qualified persons has reviewed and approved the technical information contained in this news release that is relevant to his area of responsibility and verified the data underlying such technical information.

About Excelsior

Excelsior is a mineral exploration and development company that is advancing the Gunnison Copper Project. The Excelsior management team consists of experienced professionals with proven track records of advancing mining projects into production.

Prior to the release of the Report on the PFS results, additional information about the Gunnison Copper Project can be found in the technical report filed on SEDAR at www.sedar.com entitled: "Gunnison Copper Project Preliminary Economic Assessment, NI 43-101 Technical Report" dated November 18, 2011.

For more information on Excelsior, please visit our website at www.excelsiormining.com.

ON BEHALF OF THE EXCELSIOR BOARD

Stephen Twyerould, President & CEO

Cautionary Note Regarding Forward-Looking Information

This news release contains "forward-looking information" concerning anticipated developments and events that may occur in the future. Forward looking information contained in this news release includes, but is not limited to, statements with respect to: (i) the estimation of mineral resources and mineral reserves; (ii) the robust economics, potential returns associated with the Gunnison Project, (iii) the technical viability of the Gunnison Project; (iv) the market and future price of copper; (v) expected infrastructure requirements; (vi) the results of the PFS including statements about future production, future operating and capital costs, the projected IRR, NPV, payback period, construction timelines, permit timelines and production timelines for the Kami Property, (vii) expected acid consumption rates; and (viii) the ability to mine the Gunnison Project using in-situ recovery mining techniques.

In certain cases, forward-looking information can be identified by the use of words such as "plans", "expects" or "does not expect", "is expected", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates" or "does not anticipate", or "believes", or variations of such words and phrases or state that certain actions, events or results "may", "could", "would", "might" or "will be taken", "occur" or "be achieved" suggesting future outcomes, or other expectations, beliefs, plans, objectives, assumptions, intentions or statements about future events or performance. Forward-looking information contained in this news release is based on certain factors and assumptions regarding, among other things, the estimation of mineral resources and mineral reserves, the realization of resource and reserve estimates, copper and other metal prices, the timing and amount of future exploration and development expenditures, the estimation of initial and sustaining capital requirements, the estimation of labour and operating costs, the availability of necessary financing and materials to continue to explore and develop the Gunnison Project in the short and long-term, the progress of exploration and development activities, the receipt of necessary regulatory approvals, the completion of the permitting process, the estimation of insurance coverage, and assumptions with respect to currency fluctuations, environmental risks, title disputes or claims, and other similar matters. While the Company considers these assumptions to be reasonable based on information currently available to it, they may prove to be incorrect.

Forward looking information involves known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of the Company to be materially different from any future results, performance or achievements expressed or implied by the forward-looking information. Such factors include risks inherent in the exploration and development of mineral deposits, including risks relating to changes in project parameters as plans continue to be redefined including the possibility that mining operations may not commence at the Gunnison Project, risks relating to variations in mineral resources and reserves, grade or recovery rates resulting from current exploration and development activities, risks relating to the ability to access infrastructure, risks relating to changes in copper and other commodity prices and the worldwide demand for and supply of copper and related products, risks related to increased competition in the market for copper and related products and in the mining industry generally, risks related to current global financial conditions, uncertainties inherent in the estimation of mineral resources, access and supply risks, reliance on key personnel, operational risks inherent in the conduct of mining activities, including the risk of accidents, labour disputes, increases in capital and operating costs and the risk of delays or increased costs that might be encountered during the development process, regulatory risks, including risks relating to the acquisition of the necessary licenses and permits, financing, capitalization and liquidity risks, including the risk that the financing necessary to fund the exploration and development activities at the Gunnison Project may not be available on satisfactory terms, or at all, risks related to disputes concerning property titles and interest, environmental risks and the additional risks identified in the "Risk Factors" section of the Company's reports and filings with applicable Canadian securities regulators.

Although the Company has attempted to identify important factors that could cause actual actions, events or results to differ materially from those described in forward-looking information, there may be other factors that cause actions, events or results not to be as anticipated, estimated or intended. Accordingly, readers should not place undue reliance on forward-looking information. The forward-looking information is made as of the date of this news release. Except as required by applicable securities laws, the Company does not undertake any obligation to publicly update or revise any forward-looking information.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release, and no securities regulatory authority has either approved or disapproved of the contents of this release.