Excelsior Mining Corp.: Hydrology Tests Confirm Suitable Conditions for In-Situ Recovery at Gunnison

VANCOUVER, BRITISH COLUMBIA--(Marketwire - Feb. 5, 2013) - Excelsior Mining Corp. (TSX VENTURE:MIN)(OTCQX:EXMGF)(FRANKFURT:3XS) ("Excelsior" or "the Company") is pleased to announce results from recent hydrological tests conducted at the Gunnison Copper Project, located in southeastern Arizona.

Aquifer testing at well NSH-5 indicated a hydraulic conductivity (K) of approximately 5 feet per day (ft/day) while aquifer testing at well NSH-4B had a K value of approximately 0.5 ft/day. These results confirm Excelsior's hydro-geological model and are higher than the average hydrologic conductivity of 0.4 ft/day (160 millidarcys) used in the Preliminary Economic Assessment (see news release dated December 1, 2011).

"We are very pleased with these results as they demonstrate not only our ability to predict hydrological conditions using our 3D structural model, but also demonstrate our ability to reproduce earlier results demonstrating the viability of in-situ recovery methods for our Gunnison Copper Project," says Stephen Twyerould, President and CEO of Excelsior.

The locations of these two wells were selected in order to validate the predicted aquifer conditions within highly and moderately fractured zones of the Gunnison Project's North Star deposit. Hydraulic conductivity is a measure of the efficiency with which water moves through rock; it is measured in feet per day and/or millidarcys.

Further results are expected this quarter, including new metallurgical data and new geological and resource models. All of these data will be used to complete a Pre-Feasibility study expected later this year.

Hydrology Details

Excelsior's new 3D structural geological model allows for the prediction of structural domains throughout the deposit, which in turn allow for the prediction of permeability conditions. From this structural model two sites were identified to validate the model and generate additional hydrological data for the up-coming Pre-Feasibility study. The locations were chosen to test medium and high flow zones representing the bulk of the copper oxide mineralization within the North Star deposit.

Five day constant rate pump tests were completed on wells NSH-5 and NSH-4B. These wells were surrounded by 13 observation wells at different radial locations and distances from the pumping wells. Both drawdown and recovery phases of the test were monitored in the individual test wells and observation wells. In addition, extensive geophysical logging, geological logging, assaying, and water quality sampling were completed for the test wells and various observation wells.

Well NSH-5 aquifer testing data indicated a hydraulic conductivity value of about 5ft/day, measured over an interval from 724 to 1,024 feet below surface. Well NSH-4B aquifer testing data indicated a hydraulic conductivity value of about 0.5 ft/day over an interval from 685 to 1,031 feet below surface.

These results are consistent with previous hydrological testing performed at the North Star Deposit (see news release dated September 6, 2011), and are consistent with K values from similar ISR projects.

Project Summary

The Gunnison Copper Project is located in a remote section of Cochise County in southeastern Arizona. The focus of the project is the North Star deposit, which currently has a total Indicated mineral resource of 3.21 billion pounds of oxide copper (511 M tons at 0.31%) and an Inferred mineral resource of 0.88 billion pounds of oxide copper (159 M tons at 0.28%). This oxide mineral resource has the potential to be mined using in-situ recovery methods. Please note, mineral resources which are not mineral reserves do not have demonstrated economic viability.

About Excelsior

Excelsior is an exploration company with a copper project located within the Copper Porphyry Belt of Arizona. The Gunnison Copper Project is located close to the required infrastructure and its oxide resource has the potential to be mined using in-situ recovery methods. The Excelsior team consists of experienced professionals with proven track records of advancing projects towards production.

Tim Oliver, P.E., Mining Services Manager at Haley & Aldrich, Inc., Tucson, AZ, reviewed the well construction, test protocol, results and calculations disclosed in this news release and finds them sound and reasonable. Mr. Oliver is a Qualified Person (QP) as defined by NI 43-101.

Excelsior's exploration work on the Gunnison Property is supervised by Dr. Stephen Twyerould, Fellow of AUSIMM, President and CEO of Excelsior, and a Qualified Person as defined by NI 43-101. Dr. Twyerould has reviewed and approved the technical information disclosed in the "Project Summary" and "About Excelsior" sections of this news release.

Further details about Excelsior can be found at: http://www.excelsiormining.com. Further 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.

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 inferred and indicated mineral resources; (ii) success of exploration activities; (iii) production from the Gunnison Project; and (iv) the ability to mine Gunnison using in-situ recovery mining techniques are forward-looking statements.

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, the realization of resource 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 environmental assessment 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, 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 Annual Information Form for the most recently completed financial year or other reports and filings with applicable Canadian securities regulations.

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.