Excelsior Commences Feasibility Data Collection Program

VANCOUVER, BRITISH COLUMBIA--(Marketwired - Sept. 9, 2014) - Excelsior Mining Corp. (TSX VENTURE:MIN)(FRANKFURT:3XS)(OTCQX:EXMGF) ("Excelsior" or the "Company") is pleased to announce that feasibility-level data collection has commenced at the Gunnison Copper Project in Arizona. This work will include archeological surveys, detailed site surveys, infrastructure and water studies. Data collection for input into the Feasibility Study will continue into 2015.

In addition to the data collection program, Excelsior is expected to shortly announce details concerning Metallurgical, Hydrological and Resource Upgrade drill programs. Information on these programs will be revealed in subsequent news releases.

Commenting on this news, Stephen Twyerould, President & CEO commented, "With the Gunnison Project now well-funded, we will begin the next phase of development in earnest. Going forward our sole focus will be on commencement of permitting and completion of a full Feasibility Study, leveraging the work done for completion of the Prefeasibility Study."

In January of this year, the Company announced 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 technical report summarizing the results of the PFS was prepared in accordance with National Instrument ("NI") 43-101 and is available on SEDAR at www.sedar.com and Excelsior's website.

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 $284.84 million
• Average life-of-mine operating costs of US$0.69 per pound
• Other costs of $0.13 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.

Results of the PFS disclosed in this press release are in USD and pre-tax (except where otherwise indicated).

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. Further information about the Gunnison Copper Project and the results of the PFS can be found in the technical report filed on SEDAR at www.sedar.com entitled: "Gunnison Copper Project, NI 43-101 Technical Report, Prefeasibility Study" dated February 14, 2014.

Dr. Stephen Twyerould, Fellow of AUSIMM, President and CEO of Excelsior, and a Qualified Person as defined by NI 43-101, has reviewed and approved the technical information disclosed in this news release.

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

ON BEHALF OF THE EXCELSIOR BOARD

Mark J. Morabito, Executive Chairman

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 details of the data collection program; (ii) the timing of the Feasibility Study; (iii) the commencement of drill programs; (iv) the advancement of the Gunnison Project; (v) the technical viability of the Gunnison Project; (vi) the future price of copper; (vii) the results of the PFS including statements about future production, future operating and capital costs, the projected IRR, NPV and payback period; and (viii) the ability to mine the Gunnison Project using in-situ recovery mining techniques.

Such forward-looking information can be identified by the use of word "will". 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.