Osisko Intersects 5.5 g/t Au Over 54.0 Metres at Upper Beaver

MONTREAL, QUEBEC--(Marketwire - Jan. 30, 2013) - Osisko Mining Corporation (TSX:OSK)(FRANKFURT:EWX) is pleased to announce results from the ongoing diamond drill program at the Upper Beaver gold project located in Kirkland Lake, Ontario. The Upper Beaver project is 100% owned by Osisko Mining Ltd., a wholly-owned subsidiary of Osisko.

Highlights from the new holes include 5.5g/t Au over 54.0 metres, including 18.7 g/t Au with 1.9% Cu over 11.0 metres (infill hole UB12-262W3); 16.9 g/t Au over 13.0 metres (infill hole UB12-262W2); and 27.7 g/t Au over 4.0 metres (hole UB12-269W1) in a new step-out.

The tabled results (see below) represent 30 new (and wedge) holes (19,883 metres total drilling) completed in Q4 2012 as part of the in-fill resource definition and step-out exploration program at Upper Beaver.

In-fill Resource Definition

In-fill drilling continues to confirm the continuity and high-grade nature of the core of the deposit. Seven wedge holes on the west portion of the deposit intersected significant mineralization. One hole and three wedges at the -700 m elevation of the deposit returned intervals in the Porphyry Zone assaying 12.8 g/t Au with 0.87% Cu over 9.0 m (including 36.8 g/t Au with 1.48% Cu over 3.0 m) in hole UB12-262; 1.9 g/t Au with 0.18% Cu over 22.7 m in hole UB12-262W1; 16.9 g/t Au with 0.20% Cu over 13.0 m (including 89.9 g/t Au with trace Cu over 2.0 m) in hole UB12-262W2; and 5.5 g/t Au with 0.6% Cu over 54.0 m in hole UB12-262W3. The thick interval in UB12-262W3 includes three sub-zones, 18.7 g/t Au with 1.9% Cu over 11.0 m, 2.3 g/t Au with 0.4% Cu over 14.0 m and 6.5 g/t Au with 0.4% Cu over 7.0 m.

Four wedge holes between -900 m and -1100 m intersected the Porphyry Zone, returning 15.1 g/t Au with 0.6% Cu over 3.0 m (hole UB12-161W9); 3.2 g/t Au with 0.7% Cu over 11.0 m (hole UB12-161W10); 4.2 g/t Au with 0.4% Cu over 6.0 m (hole UB12-161W11); and 3.6 g/t Au with trace Cu over 5.0 m (hole UB12-161W12).

Four holes targeted the Porphyry Zone on the east portion of the deposit. Holes UB12-254 and UB12-254W1 intersected the zone at -600 m below surface, respectively assaying 3.1 g/t Au with 0.3% Cu over 26.0 m (including 9.7 g/t Au with 0.3% Cu over 6.0 m), and 12.6 g/t Au with 0.2% Cu over 6.0 m. Near -400 m depth, hole UB12-259 returned 1.5 g/t over 7.0 m, and UB12-263 returned 4.0 g/t Au over 10.0 m (including 7.1 g/t Au over 5.0 m).

Step-out Exploration

Exploration drilling has intersected significant mineralization east and west of the deposit. Seven wedge holes intersected significant mineralization from near surface to -500 m approximately 50 m west of the existing mineral resource. Significant intersections include 27.7 g/t Au over 4.0 m (hole UB12-269W1); 41.6 g/t Au over 1.0 m and 9.1 g/t Au with 1.1% Cu over 2.0 m (hole UB12-260); 11.0 g/t Au over 1.0 m and 6.2 g/t Au over 4.0 m (hole UB12-265); 10.5 g/t Au over 1.0 m (hole UB12-269); and 0.9 g/t Au with 0.4% Cu over 19.0 m (hole UB12-257).

Six wedge holes intersected significant mineralization (expanding the footprint of the deposit) approximately 100 m - 300 m east of the known mineral resource. Significant intersections returned 5.6 g/t Au over 6.0 m and 3.4 g/t Au over 10.0 m (hole UB12-250W1) at a depth of -700 m; 4.8 g/t Au over 4.0 m (hole UB12-270) near - 150 m depth; and 18.2 g/t Au over 1.0 m (hole UB12-274) near -150 m depth.

About Upper Beaver

The Upper Beaver mine produced approximately 140,000 oz of gold and 12 million pounds of copper intermittently from 1912 to 1971, from 526,678 tonnes averaging 8.31 g/t Au and 1.03% Cu. Queenston commenced exploration on the property in 2005 and defined the first new mineral resource in 2009. Since 2005 three-hundred and eighty new diamond drill holes (including wedges) have been completed on the property, representing 236,874 metres of drilling.

A Preliminary Economic Assessment ("PEA") was completed on Upper Beaver in early 2012 (Queenston press release, February 16, 2012). The PEA studied the economics of building a 2,000 tonne per day mine/mill complex at Upper Beaver that would produce on average 120,000 oz of gold and 5.3 million pounds of copper annually with first production targeted in 2016. The permit to sink a new 1,300 m deep shaft was received in September 2012 and detailed engineering, procurement and shaft collar excavation have commenced. The PEA incorporated the May 2011 mineral resource for Upper Beaver, containing 3,074,000 t averaging 7.0 g/t Au (690,000 oz) with 0.5% Cu (36.6 M lbs) (Indicated) and 3,093,000 t averaging 6.2 g/t Au (616,000 oz) with 0.4% Cu (28.0 M lbs) (Inferred) (Queenston press release, May 4, 2011).

An updated mineral resource was announced on September 2012, increasing the indicated resource by 112% to 6,870,000 t averaging 6.6 g/t Au (1,461,000 oz) and 0.37% Cu (56 M lbs), and increasing the inferred resource by 16% to 4,570,000 t averaging 4.9 g/t Au (712,000 oz) and 0.32% Cu (32 M lbs) (Queenston press release, September 26, 2012).

The focus at Upper Beaver for 2013 will be on the development of the 1,300 metre exploration shaft, including engineering, design and fabrication of the head frame and hoisting facilities. The shaft collar has been established and exploration on the deposit continues with six drills.

Quality Control

All NQ core assays reported were obtained by standard 30 g fire-assaying-AA finish or gravimetric finish at Swastika Laboratories of Swastika, Ontario. Drill program design, Quality Assurance/Quality Control and interpretation of results is performed by qualified persons employing a QA/QC program consistent with NI 43-101 and industry best practices. The Upper Beaver project is supervised by Mark Masson, P.Geo. Standards and blanks are submitted every 25 samples for QA/QC purposes by the Company as well as the lab. Approximately 5% of sample rejects and/or pulps are sent to secondary laboratories for check assaying.

Mr. William McGuinty, P.Geo. is Project Manager for Osisko Mining Ltd. and is the Qualified Person responsible for the technical information reported herein, including verification of the data disclosed.

About Osisko

Osisko Mining Corporation operates the Canadian Malartic Gold Mine in Malartic, Quebec and is carrying out aggressive exploration and project development elsewhere in Canada and Latin America.

Cautionary Notes Concerning Estimates of Mineral Resources

This news release uses such terms as measured, indicated and inferred resources as a relative measure of the level of confidence in the resource estimate. Readers are cautioned that mineral resources are not economic mineral reserves and that the economic viability of resources that are not mineral reserves has not been demonstrated. In addition, inferred resources are considered too geologically speculative to have any economic considerations applied to them. Under Canadian rules, estimates of inferred mineral resources may not be used in the determination of feasibility or pre-feasibility studies or economic studies except for a Preliminary Assessment as defined under NI 43-101. It cannot be assumed that all or any part of an inferred mineral resource will ever be upgraded to a higher category. Readers are cautioned not to assume that further work to improve mineral resources will lead to determination of mineral reserves that can be mined economically.

Forward-Looking Statements

Certain statements contained in this press release may be deemed "forward-looking statements". All statements in this release, other than statements of historical fact, that address events or developments that Osisko expects to occur, are forward looking statements. Forward looking statements are statements that are not historical facts and are generally, but not always, identified by the words "expects", "plans", "anticipates", "believes", "intends", "estimates", "projects", "potential", "scheduled" and similar expressions, or that events or conditions "will", "would", "may", "could" or "should" occur including, without limitation, the continued development of the Upper Beaver project and more specifically the development of the exploration shaft. Although Osisko believes the expectations expressed in such forward-looking statements are based on reasonable assumptions, including, without limitation, that all technical, economical and financial conditions will be met in order to achieve such events qualified by the foregoing cautionary note regarding forward looking statements, such statements are not guarantees of future performance and actual results may differ materially from those in forward looking statements. Factors that could cause the actual results to differ materially from those in forward-looking statements include gold prices, access to skilled consultants, mining development and construction personnel, results of exploration and development activities, Osisko's limited experience with production and mining operations, uninsured risks, regulatory framework and changes, defects in title, availability of personnel, materials and equipment, timeliness of government approvals, actual performance of facilities, equipment and processes relative to specifications and expectations, unanticipated environmental impacts on operations market prices, continued availability of capital and financing and general economic, market or business conditions. These factors are discussed in greater detail in Osisko's most recent Annual Information Form and in the most recent Management Discussion and Analysis filed on SEDAR, which also provide additional general assumptions in connection with these statements. Osisko cautions that the foregoing list of important factors is not exhaustive. Investors and others who base themselves on forward-looking statements should carefully consider the above factors as well as the uncertainties they represent and the risk they entail. Osisko believes that the expectations reflected in those forward-looking statements are reasonable, but no assurance can be given that these expectations will prove to be correct and such forward-looking statements included in this press release should not be unduly relied upon. These statements speak only as of the date of this press release.

Table 1. Significant Upper Beaver Assay Results (January 2013)

Hole #	From (m)	To (m)	Interval (m)	Cu (%)	Au (g/t)	Comment
UB12-161W9	1022.0	1024.0	2.0	0.33	5.59	Infill - NC West
	1096.0	1099.0	3.0	0.56	15.14	Infill - Porphyry Zone West
UB12-161W10	1094.0	1105.0	11.0	0.66	3.19	Infill - Porphyry Zone West
UB12-161W11	1053.0	1067.0	14.0	0.21	2.43	Infill - Porphyry Zone West
including	1053.0	1059.0	6.0	0.37	4.18	Infill - Porphyry Zone West
and	1057.0	1059.0	2.0	0.51	9.33	Infill - Porphyry Zone West
UB12-161W12	968.0	970.0	2.0	trace	5.28	Infill - Porphyry Zone West
	1038.0	1043.0	5.0	trace	3.64	Infill - Porphyry Zone West
including	1041.0	1042.0	1.0	trace	15.09	Infill - Porphyry Zone West
UB12-250W1	877.0	883.0	6.0	trace	5.64	Exploration - FW East
including	880.0	883.0	3.0	trace	9.70	Exploration - FW East
	892.0	902.0	10.0	trace	3.43	Exploration - FW East
including	896.3	898.0	1.7	trace	12.28	Exploration - FW East
UB12-250W2	783.0	785.0	2.0	trace	2.87	Exploration - Porphyry Zone East
	795.0	796.0	1.0	trace	4.52	Exploration - Porphyry Zone East
	839.0	840.0	1.0	trace	3.53	Exploration - FW East
UB12-254	641.0	667.0	26.0	0.33	3.14	Infill - Porphyry Zone East
including	661.0	667.0	6.0	0.28	9.67	Infill - Porphyry Zone East
and	666.0	667.0	1.0	trace	44.36	Infill - Porphyry Zone East
UB12-254W1	644.0	650.0	6.0	0.20	12.59	Infill - Porphyry Zone East
including	647.0	648.0	1.0	0.38	57.90	Infill - Porphyry Zone East
UB12-257	67.0	86.0	19.0	0.39	0.95	Exploration - West
	170.0	184.0	14.0	0.17	0.86	Exploration - West
	224.0	245.0	21.0	0.24	0.73	Exploration - West
	315.0	340.0	25.0	0.18	0.80	Exploration - West
	363.0	370.0	7.0	0.17	2.06	Exploration - West
UB12-259	534.0	536.0	2.0	trace	5.86	Infill - NC East
	591.0	598.0	7.0	trace	1.48	Infill - Porphyry Zone East
UB12-260	60.0	66.0	6.0	0.19	1.06	Exploration - West
	199.0	200.0	1.0	trace	41.63	Exploration - West
	293.0	302.0	9.0	0.48	2.46	Exploration - West
including	296.0	298.0	2.0	1.14	9.09	Exploration - West
	430.0	466.0	36.0	0.23	0.45	Exploration - West
	649.0	650.0	1.0	trace	8.57	Exploration - West
UB12-262	605.0	608.0	3.0	trace	5.99	Infill - NC West
	715.0	717.0	2.0	trace	12.94	Infill - NC West
	785.0	794.0	9.0	0.87	12.80	Infill - Porphyry Zone West
including	791.0	794.0	3.0	1.48	36.77	Infill - Porphyry Zone West
UB12-262W1	762.0	784.7	22.7	0.18	1.92	Infill - Porphyry Zone West
	787.7	788.8	1.1	0.62	5.69	Infill - Porphyry Zone West
UB12-262W2	693.0	695.0	2.0	trace	5.33	Infill - NC West
	766.0	779.0	13.0	0.20	16.86	Infill - Porphyry Zone West
including	776.0	778.0	2.0	trace	89.98	Infill - Porphyry Zone West
	782.0	789.0	7.0	0.12	3.19	Infill - Porphyry Zone West
UB12-262W3	830.0	884.0	54.0	0.60	5.54	Infill - Porphyry Zone West
including	830.0	841.0	11.0	1.89	18.65	Infill - Porphyry Zone West
and	851.0	865.0	14.0	0.40	2.25	Infill - Porphyry Zone West
and	869.0	876.0	7.0	0.42	6.49	Infill - Porphyry Zone West
UB12-263	551.0	567.0	16.0	trace	2.79	Infill - Porphyry Zone West
including	558.0	568.0	10.0	trace	4.05	Infill - Porphyry Zone West
including	560.0	565.0	5.0	trace	7.06	Infill - Porphyry Zone West
UB12-264	153.0	155.0	2.0	trace	2.09	Exploration - West
UB12-265	341.0	342.0	1.0	trace	11.01	Exploration - West
	561.0	565.0	4.0	0.11	6.16	Exploration - West
UB12-266	331.0	332.0	1.0	trace	2.32	Exploration - East
UB12-267	579.0	580.0	1.0	trace	10.35	Infill - Porphyry Zone East
UB12-268	618.0	624.0	6.0	0.26	0.88	Exploration - West
UB12-269	568.0	569.0	1.0	trace	5.07	Exploration - West
	575.0	576.0	1.0	0.37	5.35	Exploration - West
	803.0	804.0	1.0	trace	10.46	Exploration - West
UB12-269W1	580.0	582.0	2.0	0.15	3.29	Exploration - West
	592.0	596.0	4.0	trace	27.66	Exploration - West
	830.0	832.0	2.0	trace	3.45	Exploration - West
UB12-270	227.0	231.0	4.0	trace	4.77	Exploration - East
including	228.0	229.0	1.0	trace	15.19	Exploration - East
UB12-271	19.0	22.0	3.0	trace	1.36	Exploration - East
	31.0	32.0	1.0	trace	6.61	Exploration - East
UB12-272	638.0	639.0	1.0	trace	1.92	Exploration - East
	741.9	743.0	1.1	trace	4.01	Exploration - East
UB12-274	198.0	199.0	1.0	trace	18.24	Exploration - East
	244.0	249.0	5.0	trace	2.17	Exploration - East

NOTE: True widths are interpreted based on drill-hole intercepts and interpreted orientations of intersected lithologies and are estimated at 65-80% of the core length interval. Assays are uncut. Intercepts occur within geological confines of major zones but have not been correlated to individual vein domains at this time. Holes UB12-258, UB12-261 and UB12-273 intersected no significant value. NC=North Contact Zone, FW=Footwall Zone.