TORONTO, ONTARIO--(Marketwired - Jan. 10, 2018) - Osisko Mining Inc. (TSX:OSK) (the "Corporation") announces that it has filed an early warning report in respect of its holdings in Beaufield Resources Inc. ("Beaufield"). The Corporation, through its wholly-owned subsidiary O3 Investments Inc., acquired beneficial ownership of, or control and direction over, 16,923,500 common shares of Beaufield (collectively, the "Purchased Shares" and each, a "Purchased Share") by way of a share purchase agreement transaction (and not through the facilities of the TSX Venture Exchange), representing approximately 8.2% of the issued and outstanding common shares of Beaufield ("BFD Shares") at a price of $0.14 per BFD Share for total consideration of $2,369,290 (the "Purchase"). After giving effect to the Purchase, the Corporation, through its wholly-owned subsidiary O3 Investments Inc., acquired beneficial ownership of, or control and direction over, additional BFD Shares in an amount equal to more than 2% of the outstanding BFD Shares, thereby triggering the requirement to file an early warning report.

Prior to giving effect to the Purchase, the Corporation, through its wholly-owned subsidiary O3 Investments Inc., held beneficial ownership of, or control and direction over, 39,197,300 BFD Shares, representing approximately 18.8% of the number of issued and outstanding BFD Shares. After giving effect to the Purchase, the Corporation, through its wholly-owned subsidiary O3 Investments Inc., held beneficial ownership of, or control and direction over, 56,181,300 BFD Shares, representing approximately 27.0% of the number of issued and outstanding BFD Shares.

The Corporation, through its wholly-owned subsidiary O3 Investments Inc., acquired the Purchased Shares for investment purposes. The Corporation has no current intention of increasing or decreasing its ownership of, or control or direction over, additional securities of Beaufield. The Corporation reviews its holdings from time to time and may increase or decrease its position as future circumstances may dictate.

The Corporation completed the Purchase in reliance on the private agreement exemption in section 4.2 of National Instrument 62-104 - Take-Over Bids and Issuer Bids ("NI 62-104"). The Corporation purchased the Purchased Shares from fewer than 5 sellers and at a price less than 115% of the market price, in each case as calculated in NI 62-104.

This news release is being issued in accordance with National Instrument 62-103 - The Early Warning System and Related Take-Over Bid and Insider Reporting Issues in connection with the filing of an early warning report dated January 10, 2018. The early warning report respecting the Purchase has been filed on System for Electronic Document Analysis and Review ("SEDAR") at www.sedar.com under Beaufield's issuer profile. To obtain a copy of the early warning report filed by the Corporation, please contact John Burzynski at (416) 363-8653 or refer to the SEDAR at www.sedar.com under Beaufield's issuer profile.

For further information on the Corporation please contact:

John Burzynski

President & Chief Executive Officer

Telephone: (416) 363-8653

The Corporation's head office is located at 155 University Avenue, Suite 1440, Toronto, Ontario M5H 3B7.