TORONTO, ONTARIO--(Marketwired - June 1, 2017) - Eastmain Resources Inc. ("Eastmain" or the "Company") (TSX:ER) is pleased to announce additional assay results from its 55,700 m mineral resource definition drill program at the Eau Claire deposit, located in James Bay, Québec (see FIGURES 1-4). The Company's 100%-owned Clearwater Project hosts the Eau Claire gold deposit.

Assay results are from 24 drill holes (7,317 m), including infill and step-out drill holes in the 450W Zone (4,790 m) and the 850W Zone (2,527 m). Reported exploration and infill drill holes from the program now total 173 (54,339 m), with assays pending on 9 holes.

Highlights from Eau Claire intercepts include:

• Near surface (maximum vertical depth of 100 m) results:
  • ER17-727 - 34.5 g/t Au over 1.5 m, incl. 50.0 g/t Au over 0.5 m
  • ER17-730 - 48.8 g/t Au over 0.5 m
  • ER17-757 - 21.8 g/t Au over 1.1 m, incl. 37.4 g/t Au over 0.6 m
• Shallow underground (vertical depth 100 - 400 m) results:
  • ER17-720 - 10.2 g/t Au over 8.5 m, incl. 24.3 g/t Au over 2.0 m
  • ER17-744 - 5.36 g/t Au over 5.4 m, incl. 13.3 g/t Au over 1.9 m
  • ER17-729 - 6.10 g/t Au over 3.5 m, incl. 10.8 g/t Au over 1.5 m

Claude Lemasson, Eastmain's President & CEO commented, "The resource definition program is updating the potential open pit and shallow underground mining concept for the forthcoming mineral resource estimate expected in Q3 2017. The results to date are reinforcing the strength of the Eau Claire deposit within the top 400 m. With the infill program now complete, we can focus our attention both below the 400 m levels at Eau Claire and to the east of the deposit, where minimal drilling exists, but where we see great potential for further resource growth."

The focus of the 2016/early 2017 drill program, consisting mainly of infill drilling, is to generate additional data to:

• expand our understanding of the mineralizing controls at Eau Claire,
• confirm our current geological interpretation and test the limits of mineralized envelope, and
• improve drill spacing to show continuity between veins and increase overall confidence in the deposit.

Ongoing-Drilling

Targeted exploration continues with 3 drills around the Eau Claire deposit. Drilling is focused from the 400 m to 750 m depths, targeting below the 450W and 850W zones' known measured and indicated mineral resources. In addition, new drilling is targeting the Eau Claire extension along the Clearwater Deformation Zone, towards the Snake Lake target.

High-Grade Schist (HGS)

Holes ER17-722 and ER17-726 extend potential HGS-04 mineralization by 50 m to the east and down-dip by approximately 30 m. Drill hole ER17-722 intersected the HGS-04 vein (9.30 g/t Au over 0.5 m) at a depth of 271 m and ER17-726, 25 m east, intersected two closely spaced veins (2.08 g/t Au over 2.0 m and 9.19 g/t Au over 0.5 m) in the projection of the HGS-04 vein at a vertical depth of 300 m. A shallow infill intercept of the HGS-04 vein was also intercepted in hole ER17-757 at 34 m depth in the northern portion of the 450W resource area.

Holes ER17-720 and ER17-729, located 75 m apart, both intersected infill locations in the interpreted HGS-02 vein, returning 10.2 g/t Au over 8.5 m (388 m) and 2.65 g/t Au over 6.5 m (370 m), respectively (see FIGURE 3). In addition to the HGS-02 vein, these holes and adjacent drill holes from 2016 and 2015 are defining an increased vein density. This increased density of quartz tourmaline (QT) and HGS veins is similar to clusters of veining seen elsewhere in the 450W zone, particularly in the shallow QT-type vein system (P, JQ, R, S veins) which outcrops 400 m to the northwest.

Step-out Drilling

ER17-728 drilled 300 m to the east of the 450W Zone known mineral resources and 100 m to the east of hole ER17-664 (see press release March 6, 2017). ER17-728 encountered two 1.0 m intervals, and one 0.5 m interval ranging from 1.01 to 4.96 g/t Au at depths ranging from 165 m to 340 m, generally corresponding to similar intervals in ER17-664.

Hole ER17-745, tested the continuity of vein mineralization at the northern edge of the 450W zone. The hole encountered 4 intervals within 81 m of surface with intervals ranging from 1.02 to 6.44 g/t Au over 0.5 m to 1.5 m and the 2 uppermost intervals represent easterly extensions to the G and H veins intersected 75 m to the west. Holes ER17-749 and ER17-758, located 50 m and 350 m, respectively, east of the 450W Zone mineral resources did not encounter significant mineralization.

Near-Surface Drilling - 10 - 100 m vertical depth

Shallow infill drilling at the 450W Zone confirmed the extensions of veins identified from surface outcroppings. Holes ER17-727 and 17-730 tested the NW section of the 450W zone 25 m apart, intersecting QT veins JQ, R and T in hole ER17-727 and QT veins R, S and S13 in hole ER17-730. R vein intercepts in these holes returned values of 34.5 g/t Au over 1.5 m and 48.8 g/t Au over 0.5 m respectively.

Shallow Underground Drilling - 100 - 400 m vertical depth

Infill drilling in hole ER17-744 successfully tested QT veins to a vertical depth of 300 m, intersecting the R, G S and 15 veins. An intercept of 5.36 g/t Au over 5.4 m including 13.3 g/t Au over 1.9 m was intersected in the interpreted S vein position (288 m).

850W Zone

Drilling targeted known mineralization along the northern edge of the 850W Zone from 50 m to 300 m depth. These infill holes targeted the most northerly veins in the 850W area and in some cases, were able to extend known mineralization to depth. For example, infill hole ER17-741 intersected QT vein 13 (4.20 g/t Au over 2.2 m) at shallow depth, and extended QT vein 17 (2.53 g/t Au over 6.8 m) by 25 m at 326 m vertical depth.

Narrow intervals of anomalous gold mineralization representing interpreted intersections of QT veins 13, 18, 20A and 22 were intersected in holes ER17-724, ER17-732 and ER17-748 returning results ranging to 6.0 g/t Au over intervals up to 3.0 m at depths between 75 m and 175 m depth.

Hole ER17-737 also explored the 850W Zone intersecting a narrow gold interval corresponding with QT vein 19E (75 m depth). The hole also encountered several deep intercepts between 300 and 360 m including 6.50 g/t Au over 2.0 m and 6.21 g/t Au over 1.0 m. One of these intercepts may correspond to QT vein 25 whose nearest intersection is located 100 m up dip on the same section. Additional intercepts at this depth may correspond to deep extensions of QT vein 18 (1.75 g/t over 1.6 m) or are newly encountered veins. Follow-up drilling will be conducted to further define these veins and their relationship to the 850W Zone.

A summary of selected high grade assay results from Eau Claire are presented in Table 1 below. TABLE 2 represents the complete set of significant results.

TABLE 1: Highlights from Eau Claire Drilling Results

GOLD MINERALIZATION

Gold mineralization at the Eau Claire gold deposit is generally located within approximately EW trending structurally-controlled, high-grade en-echelon quartz-tourmaline QT veins (formerly named HGV) and adjacent altered wall rocks, as well as variable width ESE trending sheared and foliated schist zones, HGS veins, of altered gold-bearing rock. HGS zones are aligned parallel to the host rock foliation and interpreted to parallel the southern, or hanging-wall side of the deposit. The vein systems are predominantly hosted within a thick sequence of massive and locally pillowed mafic volcanic flows, interbedded with narrow intervals of volcaniclastic meta-sedimentary rocks. Both flows and sediments have been intruded by multiple phases of felsic and porphyry dykes. Host rocks have been folded and deformed (sheared) through several deformation events. Both gold bearing vein sets may occur with as narrow intervals with tourmaline and develop into thick quartz-tourmaline veins with zoned tourmaline+/-actinolite+/-biotite+/-carbonate alteration halos which can measure up to several metres in thickness.

Table 3: Hole Location Information

The design of the Eastmain Resources' drilling programs, Quality Assurance/Quality Control and interpretation of results is under the control of Eastmain's geological staff, including qualified persons employing a strict QA/QC program consistent with NI 43-101 and industry best practices. The Clearwater project is supervised by Eastmain's Project Geologist, Michel Leblanc P. Geo.

Drill core is logged and split with half-core samples packaged and delivered to ALS Minerals laboratory. Samples are dried and subsequently crushed to 70% passing a 2 mm mesh screen. A 1,000 g subsample is pulverized to a nominal 85% passing 75 micron mesh screen. The remaining crushed sample (reject) and pulverized sample (pulp) are retained for further analysis and quality control. All samples are analysed by Fire Assay with an Atomic Absorption (AA) finish using a 50 g aliquot of pulverized material. Assays exceeding 5 g/t Au are re‐assayed by Fire Assay with a Gravimetric Finish. Eastmain regularly inserts 3rd party reference control samples and blank samples in the sample stream to monitor assay performance and performs duplicate sampling at a second certified laboratory. For 2016, approximately 10% of samples submitted are part of the Company's laboratory sample control protocols.

SRK Consulting (Canada) Inc. ("SRK") completed "Technical Report and Mineral Resource Estimate for the Eau Claire deposit", which reported Measured and Indicated Mineral Resources of 7.225 Million tons grading 4.09 g/t Au (951,000 ounces) of gold and Inferred resources of 3.88 Million tons grading 3.88 g/t Au (633,000 ounces) of gold. The report has an effective date of April 27, 2015 and is filed on Eastmain's SEDAR profile dated June 11, 2015.

This press release was compiled and approved by William McGuinty, P. Geo., Eastmain's VP Exploration and Qualified Person under National Instrument 43-101.

To view FIGURES 1-5, please click on the following link: http://www.eastmain.com/_resources/news/Images/ER-170601_Figures1-4.pdf

To view TABLE 2, please click on the following link: http://www.eastmain.com/_resources/news/Images/ER-170601-EC_DrillingTable2.pdf

About Eastmain Resources Inc. (TSX:ER)

Eastmain is a Canadian exploration company with 100% interest in the Eau Claire and Eastmain Mine gold deposits, both of which are located within the James Bay District of Quebec. Clearwater, host of the Eau Claire deposit, is the Company's core asset with access to superior infrastructure in a favourable mining jurisdiction. Eastmain also holds a pipeline of exploration projects in this new Canadian mining district, including being a partner in the Éléonore South Joint Venture.

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. Forward-looking statements consist of statements that are not purely historical, including statements regarding beliefs, plans, expectations or timing of future plans, and include, but not limited to, statements with respect to the potential success of the Company's future exploration and development strategies. 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, the availability of financing, timely completion of proposed studies and technical reports, and risks associated with the exploration, development and mining industry generally such as economic factors as they affect exploration, future commodity prices, changes in interest rates, safety and security, political, social or economic developments, environmental risks, insurance risks, capital expenditures, operating or technical difficulties in connection with development activities, personnel relations, the speculative nature of gold exploration and development, including the risks of diminishing quantities of grades of Mineral Resources, contests over property title, and changes in project parameters as plans continue to be refined. 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. The Company assumes no obligation to update such information, except as may be required by law.