Osisko Windfall Drilling Update: More High-Grade in Expansion and Infill

Osisko Mining Inc.

Including 203 g/t Au over 5.2 metres and 93.9 g/t Au over 7.6 metres

TORONTO, Sept. 15, 2022 (GLOBE NEWSWIRE) -- Osisko Mining Inc. (OSK:TSX. "Osisko" or the "Corporation") is pleased to provide new analytical results from the ongoing drill program at its 100% owned Windfall gold project located in the Abitibi greenstone belt, Urban Township, Eeyou Istchee James Bay, Québec.

Significant new analytical results presented below include 103 intercepts in 46 drill holes (4 from surface, 42 from underground) and 6 wedges. The infill intercepts are located inside defined mineral resource estimate (“MRE”) blocks (see Osisko news release dated August 30, 2022). The expansion intercepts are located outside the MRE blocks and either expand resource wireframes or are in a defined zone or corridor not yet correlated to a specific wireframe.

A new Lynx 4 zone announced earlier this year (see Osisko news release dated March 23, 2022) was included in the recent MRE as Lynx 4 wireframe 3466. Two expansion holes confirmed the growth potential of this wireframe with intercepts 56.9 g/t Au over 2.4 metres and 14.0 g/t Au over 2.9 metres, 170 metres and 80 metres below the current MRE blocks, respectively.

Expansion intercepts extending wireframes include: 29.1 g/t Au over 5.8 metres, a 231-meter extension of Triple Lynx wireframe 3155 below the MRE blocks, 203 g/t Au over 5.2 metres, a 33-meter extension of Triple Lynx wireframe 3120 to the west, and 51.4 g/t Au over 2.1 meters, a 39-meter extension of Triple Lynx wireframe 3161 to the east.

Infill results in this release were received after the June 7, 2022 database closed for use in the recently released MRE, and were not included. These infill results will be used in future mine planning.

Osisko Chief Executive Officer John Burzynski commented: “Our drill program continues to deliver significant high-grade results. The expansion holes continue to clearly demonstrate additional potential growth of the resource base at Windfall. As the focus shifts to engineering and the pending feasibility study, we are reducing the number of active drills at site, however we will maintain exploration work on high-potential expansion areas as well as drilling on key infill areas for mine planning.”

Select infill high-grade intercepts include: 93.9 g/t Au over 7.6 metres in WST-22-1040, 127 g/t Au over 5.7 metres in WST-22-1032; 112 g/t Au over 5.9 metres in WST-22-1033; 57.0 g/t Au over 9.3 metres in OSK-W-22-2601-W7; 53.4 g/t Au over 8.2 metres in WST-22-1026; 214 g/t Au over 2.0 metres in WST-22-1029; 176 g/t Au over 2.1 metres in WST-22-1048; 151 g/t Au over 2.2 metres in WST-22-1068 and 155 g/t Au over 2.0 metres in WST-22-1071A. Maps showing hole locations and full analytical results are available at www.osiskomining.com. Maps: Long Section_Infill EN 20220915, Long Section_LX4-3466 EN 20220915, Long Section_Expan EN 20220915, PR_EN_20220915_Surface, PR_EN_20220915_UG.

Expansion Drilling

Hole No.	From (m)	To (m)	Interval (m)	Au (g/t) uncut	Au (g/t) cut to 100 g/t	Zone	Corridor
OSK-W-19-2108-W2	1736.9	1739.3	2.4	56.9	36.3	LX4_3466	Lynx 4
including	1737.9	1738.7	0.8	162	100
OSK-W-22-2540-W13	1293.8	1296.0	2.2	7.08		LX4	Lynx 4
	1374.0	1376.4	2.4	4.57		LX4_3463	Lynx 4
	1471.1	1474.0	2.9	14.0		LX4_3466	Lynx4
including	1471.1	1472.2	1.1	27.4
OSK-W-22-2601-W7	1061.3	1067.1	5.8	29.1		TLX_3155	Triple Lynx
including	1062.2	1063.3	1.1	69.3
	1091.0	1093.0	2.0	16.3		TLX	Triple Lynx
including	1091.0	1092.0	1.0	30.1
	1126.0	1128.7	2.7	4.49		TLX	Triple Lynx
including	1127.4	1127.8	0.4	15.7
OSK-W-22-2646-W8	1037.9	1043.8	5.9	7.27		TLX_3148	Triple Lynx
	1137.5	1139.5	2.0	6.18		TLX_3162	Triple Lynx
OSK-W-22-2655	310.6	313.3	2.7	10.7		BCT	Bobcat
including	310.6	311.4	0.8	23.6
	344.0	346.0	2.0	3.64		BCT	Bobcat
	385.0	387.0	2.0	80.8	50.0	LXM	Lynx
including	385.0	386.0	1.0	162	100
	432.0	434.0	2.0	6.10		LXM	Lynx
	653.0	655.0	2.0	3.82		LSW_3508	Lynx SW
including	653.9	654.4	0.5	15.0
OSK-W-22-2656	579.0	581.2	2.2	4.57		LSW_3500	Lynx SW
WST-22-1024	160.0	162.0	2.0	5.74		TLX	Triple Lynx
including	160.0	160.6	0.6	18.9
WST-22-1025	135.4	137.7	2.3	4.10		LXM_3357	Lynx
including	137.0	137.7	0.7	11.9
WST-22-1026	351.8	354.0	2.2	4.82		TLX	Triple Lynx
including	353.1	354.0	0.9	10.8
WST-22-1032	109.0	111.1	2.1	6.17		TLX	Triple Lynx
including	109.8	110.1	0.3	17.1
	189.7	191.7	2.0	43.8	25.3	TLX	Triple Lynx
including	190.2	190.7	0.5	174	100
	205.9	208.1	2.2	24.6		TLX_3148	Triple Lynx
including	206.3	206.9	0.6	59.3
WST-22-1040	242.8	248.0	5.2	203	43.8	TLX_3120	Triple Lynx
including	246.3	248.0	1.7	586	100
WST-22-1047	41.0	43.0	2.0	125	25.2	LXM	Lynx
including	41.6	42.1	0.5	498	100
WST-22-1049	224.0	226.0	2.0	8.88		TLX	Triple Lynx
including	225.0	226.0	1.0	17.6
WST-22-1052	446.0	448.0	2.0	7.83		LX4	Lynx 4
including	447.1	447.7	0.6	25.8
WST-22-1053A	50.0	52.0	2.0	6.64		LXM	Lynx
including	50.0	50.4	0.4	33.0
WST-22-1061	142.6	144.7	2.1	51.4	43.2	TLX_3161	Triple Lynx
including	143.3	144.0	0.7	125	100
and	144.4	144.7	0.3	60.8
WST-22-1073	211.7	214.8	3.1	4.85		LHW_3216	Lynx HW
WST-22-1085	254.0	256.1	2.1	4.23		TLX_3163	Triple Lynx
including	255.2	255.5	0.3	29.2

Notes: True widths are estimated at 55 – 80% of the reported core length interval. See "Quality Control and Reporting Protocols" below., BCT = Bob Cat, LHW = Lynx Hangingwall, LSW = Lynx South West, LXM = Lynx Main, LX4 = Lynx 4 and TLX = Triple Lynx.

Infill Drilling

Hole No.	From (m)	To (m)	Interval (m)	Au (g/t) uncut	Au (g/t) cut to 100 g/t	Zone	Corridor
OSK-W-22-2120-W4	1245.9	1248.0	2.1	16.4		LX4_3449	Lynx 4
including	1246.5	1247.0	0.5	65.8
	1251.9	1254.2	2.3	3.52		LX4_3449	Lynx 4
	1263.4	1265.6	2.2	24.1		LX4_3445	Lynx 4
including	1264.2	1264.7	0.5	78.6
OSK-W-22-2601-W7	1104.0	1106.0	2.0	5.59		TLX_3162	Triple Lynx
including	1104.0	1104.5	0.5	18.2
	1112.0	1114.6	2.6	6.07		TLX_3162	Triple Lynx
including	1113.1	1113.8	0.7	17.6
	1163.7	1173.0	9.3	57.0	24.9	TLX_3172	Triple Lynx
including	1166.1	1166.6	0.5	689	100
and	1170.3	1170.8	0.5	108	100
OSK-W-22-2605-W5	1339.7	1344.0	4.3	3.52		LX4_3445	Lynx 4
OSK-W-22-2651	534.0	536.0	2.0	5.35		LSW_3508	Lynx SW
including	535.0	536.0	1.0	10.4
	563.0	565.0	2.0	5.78		LSW_3500	Lynx SW
including	564.0	565.0	1.0	11.1
OSK-W-22-2652	599.6	601.7	2.1	9.69		LSW_3500	Lynx SW
including	600.0	600.4	0.4	45.4
OSK-W-22-2656	554.4	556.4	2.0	19.9		LSW_3508	Lynx SW
including	555.0	555.5	0.5	59.1
WST-22-1026	253.6	261.8	8.2	53.4	27.0	TLX_3158	Triple Lynx
including	257.6	258.2	0.6	214	100
and	258.2	258.8	0.6	347	100
WST-22-1027	234.4	236.7	2.3	19.8		TLX_3131	Triple Lynx
	403.0	405.0	2.0	9.17		LX4_3410	Lynx 4
including	403.4	404.2	0.8	22.7
WST-22-1029	143.1	145.1	2.0	214	53.4	LXM_3388	Lynx
including	143.1	143.4	0.3	1130	100
WST-22-1032	241.3	247.0	5.7	127	50.1	TLX_3158	Triple Lynx
including	243.4	244.9	1.5	370	100
WST-22-1033	324.9	327.3	2.4	37.8		TLX_3158	Triple Lynx
including	325.6	326.4	0.8	90.2
	373.0	376.0	3.0	3.52		TLX_3155	Triple Lynx
	467.4	473.3	5.9	112	44.5	TLX_3172	Triple Lynx
including	467.8	468.4	0.6	505	100
and	469.2	470.0	0.8	240	100
WST-22-1034	169.7	173.1	3.4	26.5		LXM_3388	Lynx
including	171.8	172.4	0.6	56.6
	579.0	581.9	2.9	54.1	41.7	LX4_3430	Lynx 4
including	581.0	581.9	0.9	140	100
WST-22-1035	212.2	215.0	2.8	12.2		TLX_3148	Triple Lynx
	277.0	279.2	2.2	23.3		TLX_3158	Triple Lynx
including	278.7	279.2	0.5	93.0
WST-22-1037	212.3	214.3	2.0	10.4		TLX_3120	Triple Lynx
including	212.9	213.4	0.5	36.4
	248.0	250.2	2.2	68.4	46.6	TLX_3158	Triple Lynx
including	248.9	249.9	1.0	148	100
	336.0	338.2	2.2	6.37		TLX_3162	Triple Lynx
including	336.6	337.0	0.4	29.6
WST-22-1038	272.0	275.3	3.3	5.62		TLX_3120	Triple Lynx
	277.9	280.2	2.3	28.4	18.9	TLX_3158	Triple Lynx
including	279.8	280.2	0.4	155	100
	455.4	459.0	3.6	6.28		TLX_3172	Triple Lynx
including	458.5	459.0	0.5	37.3
WST-22-1039	255.3	258.0	2.7	25.6		TLX_3158	Triple Lynx
including	256.6	257.0	0.4	58.8
WST-22-1040	310.7	318.3	7.6	93.9	61.0	TLX_3158	Triple Lynx
including	311.7	313.1	1.4	236	100
	361.3	366.7	5.4	11.2		TLX_3162	Triple Lynx
including	363.1	364.0	0.9	46.3
	374.0	376.3	2.3	40.7	25.6	TLX_3162	Triple Lynx
including	375.9	376.3	0.4	187	100
WST-22-1041B	170.0	172.5	2.5	15.6		LXM_3388	Lynx
including	170.6	171.1	0.5	66.8
	492.0	494.0	2.0	4.21		LX4_3404	Lynx 4
including	493.0	493.7	0.7	8.43
WST-22-1042	309.1	311.3	2.2	20.5		TLX_3158	Triple Lynx
including	309.1	309.5	0.4	47.6
WST-22-1043	501.4	503.5	2.1	130	26.7	LX4_3410	Lynx 4
including	502.7	503.2	0.5	536	100
	529.9	533.1	3.2	5.60		LX4_3411	Lynx 4
including	532.6	533.1	0.5	27.8
WST-22-1044	57.0	59.2	2.2	90.2	27.0	LXM_3388	Lynx
including	58.7	59.2	0.5	378	100
WST-22-1045	233.1	236.5	3.4	7.40		TLX_3148	Triple Lynx
including	236.2	236.5	0.3	16.4
WST-22-1046B	403.0	405.3	2.3	5.55		TLX_3162	Triple Lynx
including	403.5	403.8	0.3	29.7
WST-22-1047	47.0	49.0	2.0	9.49		LXM_3354	Lynx
including	48.0	49.0	1.0	18.7
WST-22-1048	39.5	41.5	2.0	144	20.4	LXM_3354	Lynx
including	40.0	40.4	0.4	718	100
	61.4	63.5	2.1	176	34.0	LXM_3388	Lynx
including	61.9	62.6	0.7	526	100
WST-22-1052	177.0	179.0	2.0	17.7		LXM_3388	Lynx
including	177.9	178.4	0.5	40.6
	514.5	517.0	2.5	28.1		LX4_3430	Lynx 4
including	515.1	515.8	0.7	92.2
	519.0	521.0	2.0	6.81		LX4_3430	Lynx 4
WST-22-1053	48.5	50.5	2.0	8.51		LXM_3388	Lynx
including	50.0	50.5	0.5	33.8
WST-22-1058C	402.2	412.5	10.3	6.41		TLX_3162	Triple Lynx
including	405.6	406.0	0.4	95.3
WST-22-1061	112.0	114.2	2.2	15.5		TLX_3121	Triple Lynx
including	113.1	114.2	1.1	30.9
WST-22-1063A	175.3	180.3	5.0	22.4		TLX_3148	Triple Lynx
including	175.3	176.3	1.0	93.6
and	179.9	180.3	0.4	27.7
	185.0	187.0	2.0	5.35		TLX_3148	Triple Lynx
	241.3	246.2	4.9	51.7	46.6	TLX_3158	Triple Lynx
including	242.0	243.0	1.0	125	100
WST-22-1065	156.0	158.1	2.1	7.44		LXM_3317	Lynx
including	157.5	158.1	0.6	18.4
WST-22-1066	77.9	80.0	2.1	29.9		LXM_3388	Lynx
including	78.5	78.8	0.3	78.4
WST-22-1068	190.0	192.0	2.0	45.9		TLX_3161	Triple Lynx
including	191.0	191.3	0.3	96.7
	580.3	582.5	2.2	151	27.6	LX4_3430	Lynx 4
including	580.3	580.9	0.6	554	100
	586.0	588.5	2.5	52.9	23.8	LX4_3430	Lynx 4
including	586.6	587.0	0.4	282	100
WST-22-1070	161.8	163.9	2.1	62.4	38.7	TLX_3121	Triple Lynx
including	162.1	162.8	0.7	171	100
WST-22-1071A	188.0	190.9	2.9	68.9	36.4	TLX_3161	Triple Lynx
including	189.2	190.2	1.0	194	100
	203.8	205.8	2.0	155	65.5	TLX_3161	Triple Lynx
including	203.8	204.6	0.8	131	100
and	204.6	205.1	0.5	408	100
	242.0	244.0	2.0	5.63		TLX_3163	Triple Lynx
including	243.3	243.7	0.4	18.4
	264.0	266.5	2.5	9.18		TLX_3149	Triple Lynx
including	264.0	265.0	1.0	20.0
WST-22-1073	64.5	67.0	2.5	5.62		LXM_3388	Lynx
WST-22-1076	156.6	159.4	2.8	10.9		TLX_3161	Triple Lynx
including	156.6	156.9	0.3	74.0
WST-22-1078	100.6	106.1	5.5	34.6	33.2	TLX_3161	Triple Lynx
including	100.6	101.2	0.6	101	100
WST-22-1083	117.0	119.0	2.0	29.5	15.5	LXM_3317	Lynx
including	118.0	118.3	0.3	193	100
WST-22-1085	225.0	231.6	6.6	6.98		TLX_3161	Triple Lynx
including	227.0	228.0	1.0	23.0
	296.0	299.0	3.0	4.66		TLX_3158	Triple Lynx
WST-22-1090	179.2	181.7	2.5	63.1	48.7	TLX_3161	Triple Lynx
including	179.9	180.7	0.8	145	100
WST-22-1091	64.5	67.0	2.5	3.54		LXM_3388	Lynx
WST-22-1092	275.0	277.1	2.1	6.26		LHW_3212	Lynx HW
including	276.2	276.8	0.6	20.8
WST-22-1095	464.0	466.0	2.0	13.4		TLX_3162	Triple Lynx
including	465.1	466.0	0.9	28.9
	508.0	512.0	4.0	45.0	30.4	TLX_3172	Triple Lynx
including	508.7	509.2	0.5	217	100

Notes: True widths are estimated at 55 – 80% of the reported core length interval. See "Quality Control and Reporting Protocols" below., LHW = Lynx Hangingwall, LSW = Lynx South West, LXM = Lynx Main, LX4 = Lynx 4 and TLX = Triple Lynx.

Drill hole location

Hole No.	Azimuth (°)	Dip (°)	Length (m)	UTM E	UTM N	Elevation	Section
OSK-W-19-2108-W2	117	-53	2013	453215	5435858	414	3825
OSK-W-22-2120-W4	114	-60	1337	453800	5435747	401	4275
OSK-W-22-2540-W13	117	-60	1773	453466	5435639	410	3925
OSK-W-22-2601-W7	125	-61	1209	453425	5435656	412	3900
OSK-W-22-2605-W5	112	-55	1401	453551	5435669	408	4025
OSK-W-22-2646-W8	109	-58	1254	453326	5435648	414	3825
OSK-W-22-2651	146	-57	567	452988	5435242	417	3325
OSK-W-22-2652	143	-55	633	453010	5435274	416	3350
OSK-W-22-2655	146	-60	675	452976	5435277	411	3325
OSK-W-22-2656	147	-56	672	452941	5435243	411	3275
WST-22-1024	131	-57	271	453701	5435376	-198	4000
WST-22-1025	122	-20	189	453507	5435332	-47	3825
WST-22-1026	153	-65	361	453646	5435347	-189	3950
WST-22-1027	138	-30	468	453444	5435276	-99	3725
WST-22-1029	155	-40	180	453506	5435331	-47	3825
WST-22-1032	147	-61	268	453646	5435347	-188	3950
WST-22-1033	128	-63	508	453510	5435330	-127	3825
WST-22-1034	130	-45	625	453507	5435331	-48	3825
WST-22-1035	122	-60	325	453701	5435376	-198	4000
WST-22-1037	163	-63	342	453646	5435347	-188	3950
WST-22-1038	170	-67	490	453645	5435346	-189	3950
WST-22-1039	113	-55	312	453701	5435376	-198	4000
WST-22-1040	134	-60	480	453510	5435330	-127	3825
WST-22-1041B	127	-43	585	453507	5435331	-48	3825
WST-22-1042	108	-57	342	453701	5435376	-198	4000
WST-22-1043	133	-26	561	453344	5435312	-66	3650
WST-22-1044	138	-16	193	453647	5435347	-187	3950
WST-22-1045	104	-54	339	453702	5435376	-198	4000
WST-22-1046B	124	-58	436	453510	5435331	-127	3825
WST-22-1047	130	-12	226	453647	5435347	-187	3950
WST-22-1048	139	-1	169	453647	5435347	-187	3950
WST-22-1049	129	-44	621	453507	5435328	-90	3825
WST-22-1052	119	-42	613	453506	5435331	-48	3825
WST-22-1053	115	-13	64	453648	5435348	-187	3950
WST-22-1053A	115	-12	193	453648	5435348	-187	3950
WST-22-1058C	121	-60	520	453511	5435331	-127	3825
WST-22-1061	160	-59	166	453600	5435324	-181	3900
WST-22-1063A	119	-55	291	453702	5435377	-198	4000
WST-22-1065	106	-18	238	453648	5435348	-187	3950
WST-22-1066	104	-26	237	453648	5435348	-188	3950
WST-22-1068	122	-46	628	453507	5435328	-90	3825
WST-22-1070	167	-57	181	453645	5435346	-188	3950
WST-22-1071A	139	-59	393	453509	5435330	-127	3825
WST-22-1073	155	19	255	453701	5435376	-195	4000
WST-22-1076	177	-60	208	453599	5435324	-181	3900
WST-22-1078	186	-52	133	453599	5435324	-181	3900
WST-22-1083	123	-36	187	453702	5435377	-198	4000
WST-22-1085	134	-58	423	453509	5435330	-127	3825
WST-22-1090	145	-57	317	453509	5435330	-127	3825
WST-22-1091	152	30	254	453701	5435376	-195	4000
WST-22-1092	147	-7	349	453510	5435330	-126	3825
WST-22-1095	125	-66	561	453510	5435330	-127	3825

Bobcat
Mineralization most commonly occurs in gold-bearing quartz-pyrite veins controlled by northeast trending faults and shears and to a lesser extent in minor crustiform quartz-tourmaline-ankerite-pyrite veins and pyrite replacement zones and stockwork. Mineralization is hosted in sheared mafic volcanics, rhyolites near faults, or at the contact with felsic porphyritic intrusions.

Lynx Zone
Mineralization occurs as grey to translucent quartz-carbonate-pyrite-tourmaline veins and pyrite replacement zones and stockworks. Vein-type mineralization is associated with haloes of pervasive sericite-pyrite ± silica alteration and contain sulphides (predominantly pyrite with minor amounts of chalcopyrite, sphalerite, galena, arsenopyrite, and pyrrhotite) and local visible gold. Replacement mineralization is associated with strong pervasive silica-sericite-ankerite ± tourmaline alteration and contains disseminated pyrite from trace to 80% with local visible gold. Pyrite stockworks can form envelopes that reach several tens of metres thick. Fuchsite alteration is common and is spatially constrained to near the gabbros. Mineralization occurs at or near geological contacts between felsic porphyritic or fragmental intrusions and the host rhyolites or gabbros and locally can be hosted along the gabbro-rhyolite contact.

Qualified Person
The scientific and technical content of this news release has been reviewed, prepared and approved by Mr. Louis Grenier, M.Sc.A., P.Geo. (OGQ 800), Director of Exploration for Osisko's Windfall gold project, who is a "qualified person" as defined by National Instrument 43-101 – Standards of Disclosure for Mineral Projects ("NI 43-101").

Quality Control and Reporting Protocols
True width determination is estimated at 55-80% of the reported core length interval for the zone. Assays are uncut except where indicated. Intercepts occur within geological confines of major zones but have not been correlated to individual vein domains at this time. Reported intervals include minimum weighted averages of 3.5 g/t Au diluted over core lengths of at least 2.0 metres. NQ core assays were obtained by either 1-kilogram screen fire assay or standard 50-gram fire-assaying-AA finish or gravimetric finish at (i) ALS Laboratories in Val d'Or, Québec, Vancouver, British Colombia, Lima, Peru or Vientiane, Laos (ii) Bureau Veritas in Timmins, Ontario. The 1-kilogram screen assay method is selected by the geologist when samples contain coarse gold or present a higher percentage of pyrite than surrounding intervals. Selected samples are also analyzed for multi-elements, including silver, using a Four Acid Digestion-ICP-MS method at ALS Laboratories. Drill program design, Quality Assurance/Quality Control ("QA/QC") and interpretation of results is performed by qualified persons employing a QA/QC program consistent with NI 43-101 and industry best practices. Standards and blanks are included with every 20 samples for QA/QC purposes by the Corporation as well as the lab. Approximately 5% of sample pulps are sent to secondary laboratories for check assay.

About the Windfall Gold Deposit
The Windfall gold deposit is located between Val-d'Or and Chibougamau in the Abitibi region of Québec, Canada. The Mineral Resource Estimate (“MRE“) defined by Osisko, as disclosed in the news release dated August 30, 2022, will be further described, including the key assumptions, parameters and methods used to estimate the mineral resource estimate disclosed in the August 30, 2022, news release, in the full technical report being prepared for this updated mineral resource estimate in accordance with NI 43-101, and will be available on SEDAR (www.sedar.com) under the Corporation’s issuer profile within 45 days, and assumes a cut-off grade of 3.50 g/t Au, comprises 811,000 tonnes at 11.4 g/t Au (297,000 ounces) in the measured mineral resource category, 10,250,000 tonnes at 11.4 g/t Au (3,754,000 ounces) in the indicated mineral resource category and 12,287,000 tonnes at 8.4 g/t Au (3,337,000 ounces) in the inferred mineral resource category. The Windfall gold deposit is currently one of the highest-grade resource-stage gold projects in Canada and has world-class scale. Mineralization occurs in three principal areas: Lynx, Main, and Underdog. Mineralization is generally comprised of sub-vertical lenses following intrusive porphyry contacts plunging to the northeast. The resources are defined from surface to a depth of 1,600 metres, including the Triple 8 (TP8) zone. The resources excluding TP8 are defined from surface to a depth of 1,200 metres. The deposit remains open along strike and at depth. Mineralization has been identified at surface in some areas and as deep as 2,625 metres in others with significant potential to extend mineralization down-plunge and at depth.

About Osisko Mining Inc.
Osisko is a mineral exploration company focused on the acquisition, exploration, and development of precious metal resource properties in Canada. Osisko holds a 100% interest in the high-grade Windfall gold deposit located between Val-d’Or and Chibougamau in Québec and holds a 100% undivided interest in a large area of claims in the surrounding the Urban Barry area and nearby Quévillon area (over 2,400 square kilometres).

Cautionary Note Regarding Forward-Looking Information
This news release contains "forward-looking information" within the meaning of the applicable Canadian securities legislation that is based on expectations, estimates, projections and interpretations as at the date of this news release. Any statement that involves predictions, expectations, interpretations, beliefs, plans, projections, objectives, assumptions, future events or performance (often, but not always, using phrases such as "expects", or "does not expect", "is expected", "interpreted", "management's view", "anticipates" or "does not anticipate", "plans", "budget", "scheduled", "forecasts", "estimates", "potential", "feasibility", "believes" or "intends" or variations of such words and phrases or stating that certain actions, events or results "may", "could", "would", "might" or "will" be taken to occur or be achieved) are not statements of historical fact and may be forward-looking information and are intended to identify forward-looking information. This news release contains the forward-looking information pertaining to, among other things: the Windfall gold deposit being one of the highest-grade resource-stage gold projects in Canada and having world-class scale; the key assumptions, parameters and methods used to estimate the mineral resource estimate disclosed in this news release; the prospects, if any, of the Windfall gold deposit; the timing and ability of Osisko to file a technical report for the mineral resource estimate disclosed in this news release; the timing and ability of Osisko, if at all, to publish a feasibility study for the Windfall gold deposit; upgrading an inferred mineral resource to a measured mineral resource or indicated mineral resource category; future exploration activities, including drilling, at the Windfall gold deposit; the deposit remaining open along strike and at depth; the plunge potential of the Lynx and Underdog zones; expected grade and resource growth; cut-off grade and sensitivity analysis; and the significance of historic exploration activities and results. Although the forward-looking information contained in this news release is based upon what management believes, or believed at the time, to be reasonable assumptions, Osisko cannot assure shareholders and prospective purchasers of securities of the Corporation that actual results will be consistent with such forward-looking information, as there may be other factors that cause results not to be as anticipated, estimated or intended, and neither Osisko nor any other person assumes responsibility for the accuracy and completeness of any such forward-looking information. Such factors include, among others, risks relating to the ability of exploration activities (including drill results) to accurately predict mineralization; errors in management's geological modelling; the ability of Osisko to complete further exploration activities, including drilling; property and royalty interests in the Windfall gold deposit; the ability of the Corporation to obtain required approvals; the results of exploration activities; risks relating to mining activities; the global economic climate; metal prices; dilution; environmental risks; and community and non-governmental actions. Osisko does not undertake, and assumes no obligation, to update or revise any such forward-looking statements or forward-looking information contained herein to reflect new events or circumstances, except as may be required by law.

CONTACT INFORMATION:
John Burzynski
Chief Executive Officer
Telephone (416) 363-8653