Montreal, Quebec, December 11, 2009 — Osisko Mining Corporation (‘’Osisko’’) (TSX: OSK; Deutsche Boerse: EWX) and Clifton Star Resources (“Clifton”) (TSXV:CFO; Deutsche Boerse:C3T) are pleased to announce that they have finalized an Agreement to enter into a Joint Venture on the Duparquet Project announced on November 16, 2009.

Under the terms of the Agreement, Osisko will earn a 50% interest in the Joint Venture by investing $70 million over a 4-year period, including a firm commitment of $15 million in 2010. Osisko will act as operator of the Joint Venture during the earn-in period and thereafter as long as Osisko holds a minimum 50% interest in the Joint Venture.

Osisko has also agreed to advance up to $31 million to Clifton to fund its opt ion payments to the underlying property vendors. These advances are repayable within 24 months after disbursements, bear an annual interest rate of 5%, and are unsecured.

Osisko will also make an unsecured loan to Clifton for a principal amount of $6 million on or before January 1, 2010 for general corporate purposes. This loan will also bear interest at the rate of 5% per annum, have a term of 12 months from the date of advance, and will be evidenced by a promissory note. Clifton, at its sole option, may elect at any time to convert the entire amount of principal and interest owing under such loan into common shares of Clifton at a conversion price per share of $3.12, provided such conversion is subject to prior approval of applicable regulatory agencies and stock exchanges. The promissory note shall provide for the customary anti-dilution and conversion rights protection for the lender.

The coming into force of the Agreement remains subject to the approval of the stock exchange.

Mr. Sean Roosen, President and Chief Executive Officer of Osisko commented on the transaction: ‘‘We look forward to initiating an intensive exploration program on the Duparquet Project. We believe the project offers excellent potential for the definition of additional porphyry-hosted gold resources, and we are confident in our ability to build on the previously identified resources.’’

Mr. Harry Miller, President and Chief Executive Officer of Clifton Star commented: “We are pleased to conclude this Joint Venture Agreement, and are excited about getting Osisko’s exploration and technical teams at Duparquet. Shareholders of both Clifton Star and Osisko should be in for an exciting year ahead.”

About the Duparquet Project
The Duparquet Project is located in the Abitibi region of Quebec, approximately 90 km northwest of Osisko’s Canadian Malartic Project. It comprises two large property blocks that cover approximately 8 kilometres of strike length along the prolific Porcupine Destor Fault Zone, which has historically produced over 80 million ounces of gold. The properties host former producing underground gold mines (including the Beattie, Donchester and Duquesne mines which, collectively, produced over 1.5 million ounces of gold from 1933 – 1991) and two deposits with known gold resources (Central Duparquet and Dumico).

Clifton recently filed a NI 43-101 compliant report based on new drilling at Beattie and Donchester which outlines significa nt gold resources on the property (see Clifton press release dated September 8, 2009).

About Clifton Star
Clifton Star Resources, Inc. is a junior gold exploration company focused on developing its Duparquet and Destor Township gold properties located in northwestern Quebec. Historically, Quebec ranks as one of the most supportive mining jurisdictions in the world.

About Osisko
Osisko Mining Corporation is currently developing the Canadian Malartic gold deposit and adjacent mineralized zones into a large-scale open pit, bulk-tonnage mining operation. The Company is well-funded with $825 M in cash resources and is carrying out an aggressive mine development, reserve definition and exploration campaign. The Canadian Malartic deposit currently represents one the biggest gold reserves in Canada for a single deposit, and is still growing through ongoing drilling on new mineralized zones. Current reserves for the Canadian Malartic property are 6.28 million ounces with 183.3 Mt @ 1.07 g/t Au (proven reserves: 5.16 Mt @ 1.14 g/t Au, probable reserves: 178.2 Mt @ 1.06 g/t).

Montreal, Quebec, December 11, 2009 — Osisko Mining Corporation (‘’Osisko’’) (TSX: OSK; Deutsche Boerse: EWX) and Clifton Star Resources (“Clifton”) (TSXV:CFO; Deutsche Boerse:C3T) are pleased to announce that they have finalized an Agreement to enter into a Joint Venture on the Duparquet Project announced on November 16, 2009.

Under the terms of the Agreement, Osisko will earn a 50% interest in the Joint Venture by investing $70 million over a 4-year period, including a firm commitment of $15 million in 2010. Osisko will act as operator of the Joint Venture during the earn-in period and thereafter as long as Osisko holds a minimum 50% interest in the Joint Venture.

Osisko has also agreed to advance up to $31 million to Clifton to fund its opt ion payments to the underlying property vendors. These advances are repayable within 24 months after disbursements, bear an annual interest rate of 5%, and are unsecured.

Osisko will also make an unsecured loan to Clifton for a principal amount of $6 million on or before January 1, 2010 for general corporate purposes. This loan will also bear interest at the rate of 5% per annum, have a term of 12 months from the date of advance, and will be evidenced by a promissory note. Clifton, at its sole option, may elect at any time to convert the entire amount of principal and interest owing under such loan into common shares of Clifton at a conversion price per share of $3.12, provided such conversion is subject to prior approval of applicable regulatory agencies and stock exchanges. The promissory note shall provide for the customary anti-dilution and conversion rights protection for the lender.

The coming into force of the Agreement remains subject to the approval of the stock exchange.

Mr. Sean Roosen, President and Chief Executive Officer of Osisko commented on the transaction: ‘‘We look forward to initiating an intensive exploration program on the Duparquet Project. We believe the project offers excellent potential for the definition of additional porphyry-hosted gold resources, and we are confident in our ability to build on the previously identified resources.’’

Mr. Harry Miller, President and Chief Executive Officer of Clifton Star commented: “We are pleased to conclude this Joint Venture Agreement, and are excited about getting Osisko’s exploration and technical teams at Duparquet. Shareholders of both Clifton Star and Osisko should be in for an exciting year ahead.”

About the Duparquet Project
The Duparquet Project is located in the Abitibi region of Quebec, approximately 90 km northwest of Osisko’s Canadian Malartic Project. It comprises two large property blocks that cover approximately 8 kilometres of strike length along the prolific Porcupine Destor Fault Zone, which has historically produced over 80 million ounces of gold. The properties host former producing underground gold mines (including the Beattie, Donchester and Duquesne mines which, collectively, produced over 1.5 million ounces of gold from 1933 – 1991) and two deposits with known gold resources (Central Duparquet and Dumico).

Clifton recently filed a NI 43-101 compliant report based on new drilling at Beattie and Donchester which outlines significa nt gold resources on the property (see Clifton press release dated September 8, 2009).

About Clifton Star
Clifton Star Resources, Inc. is a junior gold exploration company focused on developing its Duparquet and Destor Township gold properties located in northwestern Quebec. Historically, Quebec ranks as one of the most supportive mining jurisdictions in the world.

About Osisko
Osisko Mining Corporation is currently developing the Canadian Malartic gold deposit and adjacent mineralized zones into a large-scale open pit, bulk-tonnage mining operation. The Company is well-funded with $825 M in cash resources and is carrying out an aggressive mine development, reserve definition and exploration campaign. The Canadian Malartic deposit currently represents one the biggest gold reserves in Canada for a single deposit, and is still growing through ongoing drilling on new mineralized zones. Current reserves for the Canadian Malartic property are 6.28 million ounces with 183.3 Mt @ 1.07 g/t Au (proven reserves: 5.16 Mt @ 1.14 g/t Au, probable reserves: 178.2 Mt @ 1.06 g/t).