Atna Completes Ni43-101 Report of Pinson Underground Gold Mine

GOLDEN, Colo., May 31, 2012 /CNW/ - Atna Resources Ltd. ("Atna" or the "Company") (TSX:ATN / OTCBB:ATNAF) has completed an NI43-101 compliant technical report for the Pinson Underground Gold Mine, located in Humboldt County, Nevada. The report demonstrates that Pinson is an economically attractive gold mining project. Atna is developing the property with gold production targeted to commence in Q4 2012. The report includes Mineral Resource and Mineral Reserve estimates, mining and processing plans, detailed project economics and sensitivity analysis.

The mine plan envisions a six-year life after the 2012 development period to recover approximately 550,000 ounces of gold at a rate of approximately 90,000 ounces per year from current Proven and Probable Mineral Reserves. There is no allowance in this projection for the possible conversion of Inferred Mineral Resource into Mineral Reserve, nor for any additional contribution from the adjacent potential open pit project.

"Return from the capital investment, expected production level, and production cost profile of the Pinson underground project exceeds Atna's targets for the project", stated James Hesketh, President and CEO. He adds that "Pinson underground is a robust project with strong economic returns from a modest capital investment. We have designed a project that trades low capital entry cost for a higher initial operating cost structure. This initial mine plan provides a road-map and highlights areas for further economic improvement with additional engineering studies. Furthermore, we believe that additional project upside may be realized from exploration potential and future conversion of a portion of Inferred Resource to Mineral Reserve."

Project economics at varying gold prices are demonstrated in the following table.

The net capital outlay for 2012 is approximately $21 million. The projected cumulative capital outlay, net of proceeds from ore sales using a $1,500 gold price, is approximately $28 million through the second quarter of 2013. The royalty, severance tax and total net capital outlays will vary as gold prices change. To conserve cash, if required, the capital outlay may be deferred, which would result in a slower than projected ramp-up in production for 2013.

The Pinson mine will utilize an underhand cut and fill mining method using cemented fill. This method was chosen due to the variable nature of the various ore-bodies and the low strengths of the ore and country rock. This method minimizes ore dilution, while recovering a high percentage of ore reserve to maximize economic return. The cut and fill mining method is currently being used in a number of mines in Nevada where ore and country rock characteristics necessitate a conservative support design to enhance miner safety. Access will be provided by ramp decline. For the foreseeable future, mining at Pinson will be performed by a contract miner and ore will be shipped to nearby third-party processing facilities. Pinson has a life-of-mine contract for the processing of sulfide ore at the Barrick Goldstrike autoclave facilities. The use of third-party sulfide ore processing, oxide ore sales, and contract mining has resulted in substantially reduced initial capital requirements for the project and has accelerated development and ramp-up.

As previously announced in the Company's 2011 year-end filings on Form 20-F dated March 26, 2012, Mineral Resources estimates for the underground portion of the Pinson Gold Mine are as follows:

The summary of Mineral Reserves by zone is shown in the following table. These Mineral Reserves are included in Measured and Indicated Mineral Resources shown above and were calculated using a three-year trailing average gold price of $1,300 per ounce.

The cut-off grade was based on an average of the calculated economic cutoff grades for both oxide and sulfide ores. Approximately 10 to 15 percent of total ore tons fall into the oxide classification.

Daily ore production starts at an average rate of 200 tons per day (tpd) in 2012, increasing to an average of approximately 750 tpd in 2013, and ultimately to an average of 1,000 tpd in 2014 through 2016, then declining into 2018. The expected life-of-mine production schedule is shown in the following table.

A summary of the cash operating costs per ton of ore mined basis is shown in the following table. These costs are based on actual contract costs, quotations and estimates for each of the cost centers shown.

Gustavson Associates LLC of Lakewood, CO has prepared the Technical Report at a level sufficient to support an initial Mineral Reserve estimate for the Pinson Project.

Mr. Donald Hulse, P.E., V.P. and Principal Mining Engineer for Gustavson, and William J. Crowl, VP Mining for Gustavson are considered Qualified Persons as defined by NI 43-101. Mr. Crowl has read this press release and approved the technical content of same.

For additional information on Atna Resources and the Pinson Gold Mine, please visit our website at www.atna.com or our filings with Canadian securities regulators on SEDAR or U.S. regulators on EDGAR.

This press release contains certain "forward-looking statements," as defined in the United States Private Securities Litigation Reform Act of 1995, and within the meaning of Canadian securities legislation relating to the Pinson Underground Mine. Forward-looking statements are statements that are not historical fact. They are based on the beliefs, estimates and opinions of the Company's management on the date the statements are made and they involve a number of risks and uncertainties. Consequently, there can be no assurances that such statements will prove to be accurate and actual results and future events could differ materially from those anticipated in such statements. The Company undertakes no obligation to update these forward-looking statements if management's beliefs, estimates or opinions, or other factors, should change, unless required by law. Factors that could cause future results to differ materially from those anticipated in these forward-looking statements include: gold deposit modeling, development and future operating costs at the Pinson Underground Mine, the Company might encounter problems such as the significant depreciation of metals prices; accidents and other risks associated with mining exploration and development operations; the risk that the Company will encounter unanticipated geological factors; the Company's need for and ability to obtain additional financing; the possibility that the Company may not be able to secure permitting and other governmental clearances necessary to carry out the Company's exploration and development programs; and the other risk factors discussed in greater detail in the Company's various filings on SEDAR (www.sedar.com) with Canadian securities regulators and its filings with the U.S. Securities and Exchange Commission, including the Company's 2011 Form 20-F dated March 26, 2012.

Cautionary Note to U.S. Investors --- The United States Securities and Exchange Commission permits U.S. mining companies, in their filings with the SEC, to disclose only those mineral deposits that a company can economically and legally extract or produce. We use certain terms in this report, such as "measured," "indicated," "inferred," and "resources," that the SEC guidelines strictly prohibit U.S. registered companies from including in their filings with the SEC.

FOR FURTHER INFORMATION, CONTACT:

James Hesketh, President and CEO - (303) 278-8464
Valerie Kimball, Investor Relations - toll free (877) 692-8182
www.atna.com

SOURCE Atna Resources Ltd.

SOURCE Atna Resources Ltd.