TORONTO, ONTARIO--(Marketwire - Oct. 11, 2012) - Eastmain Resources Inc. (News - Market indicators) is pleased to announce an updated mineral resource estimate, prepared in accordance with NI 43-101, for its 100%-owned Eau Claire gold deposit (Clearwater Project), located in the James Bay, Middle North region of Québec. The updated resource incorporates 28,523 metres of drilling completed on the deposit, since the previous estimate (NR April 26, 2011).

This updated resource, prepared by P&E Mining Consultants Inc. ("P&E"), indicates that drilling completed in 2011, along with 9 holes from 2010, have defined Measured, Indicated and Inferred gold resources from within the 850 West Zone, favourably expanding the size of potential Open Pit resources at Eau Claire. Recent 2012 drilling combined with 3D modeling of the deposit indicates that the 450 and 850 West Zones are part of a continuous gold-bearing system, which is currently being expanded to the north, west and at depth, through additional drilling.

Multiple parallel, sheeted quartz tourmaline veins and alteration zones comprising the 450 and 850 West Zones of the Eau Claire Deposit contain a combined Measured and Indicated Resource of 4.87 million tonnes with an average grade of 4.60 grams per tonne gold (g/t) for 721,000 ounces of gold (4.94 million tonnes containing 780,000 ounces at 4.91 g/t gold uncapped*). In addition, 6.4 million tonnes with an average grade of 5.45 g/t gold, classified as Inferred Resources, contain 1,122,000 ounces of gold (6.5 million tonnes containing 1,148,000 ounces at 5.48 g/t gold uncapped*).

The resource estimate considers that mineralization starts at surface and continues to a depth of approximately 900 metres. This updated resource estimate does not include results of the ongoing 40,000-metre definition drilling currently underway. The deposit remains open in all directions.

Mineral Resources above an average 220-metre depth from surface are considered to be amenable to open pit extraction, whereas mineral resources below this depth are considered to be amenable to underground extraction.

Potential open pit mineral resources are reported at a cut-off of 0.5 grams per tonne gold, whereas potential underground mineral resources are reported at a cut-off of 2.5 grams per tonne gold. The consolidated mineral resource statement for Eau Claire is tabulated in Table 1. Table 2 summarizes the uncapped*(Note 14) mineral resource sensitivity for comparative purposes.

P&E also performed a sensitivity analysis on the resource model using different gold cut-off grades as demonstrated in Table 3, which shows that there is in excess of one million total ounces of high-grade gold contained within the Measured and Indicated resource category at all cut-off grade sensitivities. At a 4.0 g/t cut-off there is a Measured resource of 976,000 tonnes at 10.62 g/t yielding 334,000 ounces of gold (capped) or an uncapped Measured resource of 1,021,000 tonnes at 12.28 g/t for 404,000 ounces of gold. An Inferred mineral resource at a 4.0 g/t cut-off consists of 611,000 tonnes containing 319,000 ounces of gold at 16.2 g/t capped grade or 325,000 ounces of gold at 18.2 g/t uncapped (Note 16).

Highlights of the Eau Claire mineral resource estimate include:

• Measured and Indicated potentially Open Pittable resources at an average grade of 4.32 grams per tonne gold (4.67 grams per tonne gold uncapped) containing 579,000 ounces gold (635,000 ounces gold uncapped);
• Inferred potentially Open Pittable resources at an average grade of 2.50 grams per tonne gold (2.68 grams per tonne gold uncapped) containing 192,000 ounces gold (213,000 ounces gold uncapped);
• Measured and Indicated potentially Underground mineable resources at an average grade of 6.29 grams per tonne gold (6.37 grams per tonne gold uncapped) containing 142,000 ounces gold (145,000 uncapped);
• Inferred potentially Underground mineable resources at an average grade of 7.20 grams per tonne gold (7.20 grams per tonne uncapped) containing 929,000 ounces gold (935,000 ounces gold uncapped).

Eastmain President and CEO, Dr. Donald J. Robinson stated "Our near-term priority is to expand mineral resources of the Eau Claire Gold Deposit which are potentially amenable to Open Pit extraction. Drilling completed in 2011 and 2012 confirms that the gold deposit continues to the west with a hinge forming between the 450 and 850 West Zones. These two zones are characterized by similar vein plus alteration mineral assemblages and precious metal suites, however, the associated gold-bearing structures have different orientations. In general, the Eau Claire gold deposit appears to form a large crescent-shaped, gold-rich system which is structurally controlled. Over 60 drill holes completed to date in 2012 provide evidence that the Eau Claire Deposit is expanding to the north, west and at depth. Since compiling this resource estimate, visible gold has been observed in another 20 drill holes, within more than 40 mineralized intervals. We believe the likelihood of adding additional resource ounces in the future is high."

There is excellent potential to expand both potential open pit and underground gold resources at Eau Claire. Several new high-grade veins, including V19 and T10, have recently been discovered in multiple drill holes north of the limits of the defined resource. A 40,000-metre, definition drill program, focused on increasing resources within the upper 300 metres from surface, is two-thirds complete. Property-scale prospecting and trenching for future resource testing also continues outside the limits of the deposit, along the favourable Eau Claire gold trend.

The Eau Claire Gold Deposit consists of a stacked series of quartz-tourmaline +/- carbonate sheeted veins (VQTL) aligned in a three-dimensional, en-echelon pattern within a structural corridor. Gold-bearing veins extend over an area of at least two kilometres in length, to a depth of over 900 metres. Gold also occurs within altered rock composed of actinolite and tourmaline, with accessory biotite and calcite, which generally forms a metric-sized envelope on vein margins. Very fine grained visible gold and tellurides are common and have been documented in over 200 drill holes and 350 mineralized intervals.

More than 50 parallel, gold-bearing quartz-tourmaline veins and alteration zones, generally ranging from one to six metres and locally up to 25 metres in width, have been intersected in the Eau Claire Deposit. These veins range from 75 to 300 metres in length and have been traced by Diamond drilling to a vertical depth of approximately 900 metres.

The 450 vein set is oriented N85°E and dips 45° to 60° south. Drilling indicates there is a pronounced plunge to the mineralized zone, defined by these veins, in a direction of approximately 45° southeast. The 850 vein set is aligned at N60°E with a subvertical alignment and southwesterly plunge. The principal host rock is a strongly deformed mafic volcanic rock. The mineralized corridor appears to be constrained by a felsic porphyry package on the hangingwall or south side and by a felsic volcaniclastic interval on the footwall or north side.

The Eau Claire gold deposit occurs two kilometres from permanent road access and 10 kilometres from Hydro Quebec's EM-1 world class hydroelectric installation. The 450 and 850 West Zones are centred on topographic highs. Trenching and drilling have also outlined a 5-kilometre-long mineralized trend, including additional topographic highs characterized by wide intervals of gold-bearing rock and high-grade quartz-tourmaline veins, comparable to those found at the Eau Claire deposit.

Notes:

1. Mineral resources which are not mineral reserves do not have demonstrated economic viability. The estimate of mineral resources may be materially affected by environmental, permitting, legal, title, taxation, sociopolitical, marketing, or other relevant issues.

2. The quantity and grade of reported Inferred resources in this estimation are uncertain in nature and there has been insufficient exploration to define these inferred resources as an indicated or measured mineral resource, and it is uncertain if further exploration will result in upgrading them to an Indicated or Measured mineral resource category.

3. The mineral resources have been classified in accordance with requirements of NI 43-101 and the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) standards, CIM Standards on Mineral Resources and Reserves, Definitions and Guidelines prepared by the CIM Standing Committee on Reserve Definitions.

4. Eugene Puritch, P.Eng., Antoine Yassa, P.Geo. and Tracy Armstrong, P.Geo. of P&E Mining Consultants Inc., Qualified Persons under NI 43-101, who are independent of the Company, are responsible for the mineral resource estimates presented.

5. The resources are estimated using the polygonal method.

6. Bulk density determinations were based on 1900 drill core measurements conducted by Lakefield (SGS Minerals) and by a previous study by COREM. Tonnage was calculated by volume x specific gravity.

7. The 0.5 g/t pit cut-off and 2.5 g/t Au underground cut-off values used in the above tables are based on the September 30, 2012 36-month trailing average gold price of US$1,436 per ounce, a US$1.00=CDN$1.00 exchange rate and 95% process recovery. The cut-off derivations also considered open pit and underground estimated operating costs of CDN$3.50/tonne and CDN$85/tonne respectively, processing costs of CDN$17/tonne and G&A costs of CDN$5/tonne.

8. The mineral resource estimate is based on 470 Diamond drill holes totaling 123,211 metres. 77 of these drill holes, totaling 28,523 metres, were completed since the last mineral resource estimate.

9. Resource parameters were calculated in GEMCOM and exported to Excel.

10. Gold assay composite intervals exceeding 100 grams per tonne have been capped to 100 grams.

11. The mineral resource estimate database includes 56,519 split core assay samples. Drill core was logged, photographed and split with half-core samples shipped to ALS Chemex Laboratories of Sudbury and SGS Minerals of Toronto.

12. For QA/QC purposes in addition to lab blanks and standards, the Company inserts alternating blanks and standards every 25 samples. Standards were purchased from Analytical Solutions Ltd, of Toronto.

13. Figures may not total due to rounding.

14. *Uncapped resources utilizing the maximum gold values are only a sensitivity to the actual capped resource estimate.

15. ** Eastmain has not completed a feasibility study in regards to the mineral resources presented herein and there is no certainty that proposed operations will be economically viable. Estimates refer to potential mining methods based on standard industry assumptions.

16. Detailed economic studies will be required to optimize cut-off grade, however a preliminary sensitivity analysis using various gold cut-off grades has been included as Tables 3.

The updated resource calculations and sensitivity tables were prepared by Eugene Puritch, P. Eng., and Antoine Yassa, P.Geo. of P&E Mining Consultants Inc. ("P&E") of Brampton, Ontario, Qualified Persons under NI 43-101 who are independent of the Company.

Eugene Puritch, P. Eng., President of P&E, and Dr. Donald J. Robinson P. Geo, President and Chief Executive Officer of Eastmain, both Qualified Persons under National Instrument 43-101 have reviewed and approved the updated resources and the technical data presented in this press release.

About Eastmain Resources Inc. (News - Market indicators)

Eastmain is a Canadian gold exploration company with 100% interest in the Eau Claire and Eastmain gold deposits. The Corporation has $10 Million in working capital and holds a pipeline of exploration projects within the James Bay District, including the Éléonore South property. Eastmain has allocated $7 million for drilling the Eau Claire deposit in 2012.

Forward Looking Statements - Certain information set forth in this news release may contain forward-looking statements that involve substantial known and unknown risks and uncertainties. These forward-looking statements are subject to numerous risks and uncertainties, certain of which are beyond the control of Eastmain, including, but not limited to the impact of general economic conditions, industry conditions, dependence upon regulatory approvals and the availability of financing. Readers are cautioned that the assumptions used in the preparation of such information, although considered reasonable at the time of preparation, may prove to be imprecise and, as such, undue reliance should not be placed on forward-looking statements.